Adrenocorticotropin-Dependent Ectopic Cushing’s Syndrome: A Case Report

Abstract

Paraneoplastic syndromes are rare and diverse conditions caused by either an abnormal chemical signaling molecule produced by tumor cells or a body’s immune response against the tumor itself. These syndromes can manifest in a variable, multisystemic and often nonspecific manner posing a diagnostic challenge.

We report the case of an 81-year-old woman who exhibited severe hypokalemia, metabolic alkalosis, and worsening hyperglycemia. The investigation was consistent with adrenocorticotropin (ACTH)-dependent Cushing’s syndrome and, eventually, the patient was diagnosed with stage IV primary small-cell lung cancer (SCLC).

SCLC is known to be associated with paraneoplastic syndromes, including Cushing’s syndrome caused by ectopic adrenocorticotropin (ACTH) secretion. Despite being associated with very poor outcomes, managing these syndromes can be challenging and may hold prognostic significance.

Introduction

Adrenocorticotropin (ACTH)-dependent Cushing’s syndrome (CS) is caused by excessive ACTH production by corticotroph (Cushing’s disease (CD)) or nonpituitary (ectopic) tumors, leading to excessive cortisol production. Ectopic ACTH syndrome (EAS) is a rare condition, accounting for 10 to 20% of all cases of ACTH-dependent CS and 5 to 10% of all types of CS [1]. The normal glucocorticoid-induced suppression of ACTH is reduced in ACTH-dependent CS, especially with ectopic ACTH production. Studies show that a wide variety of neoplasms, usually carcinomas rather than sarcomas or lymphomas, have been associated with EAS. Most cases are caused by neuroendocrine tumors of the lung, pancreas, or thymus, in which the hypercortisolism state is not apparent clinically, resulting, all too often, in delayed diagnosis [2,3].

Current diagnostic tests for EAS aim to confirm high cortisol levels, the absence of a cortisol circadian rhythm, as well as the reduced response to negative feedback from glucocorticoid administration, and imaging to identify the site of ACTH production.

Prompt diagnosis and management are crucial in EAS, highlighting the importance of physician awareness and early recognition of this syndrome.

Treatment options depend on the underlying tumor. Surgical removal is often the primary approach, followed by radiation therapy or chemotherapy. Additionally, medications to control cortisol levels may be necessary to manage the various comorbid conditions associated with CS, such as cardiovascular disease, diabetes, electrolyte imbalances, infections and thrombotic risk [4,5].

Case Presentation

We report the case of an 81-year-old woman with a fully active performance status (ECOG 0) and a medical history of diabetes, hypertension, dyslipidemia, and depressive disorder. She was admitted to an internal medicine ward due to an acute hydroelectrolytic disorder, including metabolic alkalosis, severe hypokalemia (2 mmol/L), hypochloremia (85 mmol/L), hypocalcemia (0.95 mmol/L), hypophosphatemia (1.4 mg/dL), hypomagnesemia (0.9 mg/dL), and hyperlactatemia (5.8 mmol/L), after she reportedly self-medicated herself with higher doses of metformin (four to five pills a day) due to high blood glucose levels. The patient presented with asthenia, nausea, vomiting, and diarrhea for three days and reported uncontrolled blood glucose levels for the last eight days.

The physical examination was unremarkable, without any altered mental status or signs of infection. Arterial blood gas samples showed metabolic alkalemia (pH 7.59) and hyperlactatemia, associated with severe hypokalemia, normal bicarbonate (27 mmol/L), and mildly elevated glycemia and ketonemia (232 mg/dL and 1.7 mmol/L, respectively). Lab tests confirmed the serum potassium levels as well as the other aforementioned electrolyte disturbances. Kidney function and hepatic enzymes were normal. Considering the possible relationship between the electrolyte disorder and the gastrointestinal presentation, the patient was given intravenous (IV) fluids and received potassium and magnesium replacement therapy.

Despite receiving 200 milliequivalents (mEq) of IV potassium chloride and 4 grams of magnesium sulfate, in the first 48 hours, the ion deficits persisted. Given the persistent electrolyte derangement, the patient was admitted to the Internal Medicine ward for etiological investigation and monitoring of ionic correction. The initial period was remarkable for refractory hypokalemia and uncontrolled diabetes under respective therapeutic measures, including 80 to 130 mEq of IV potassium chloride and progressive titration of spironolactone to 200 mg a day. Laboratory investigation revealed high parathormone levels (PTHi 167 pg/mL; reference range: 10-65 pg/mL), vitamin D deficiency (3.3 ng/mL; reference range >20 ng/mL) and apparent ACTH-dependent hypercortisolism (serum cortisol 80.20 ug/dL; ACTH 445 pg/mL), as well as high urinary potassium and glucose concentrations (190 mEq/24 h and 21161 mg/24 h). A dexamethasone suppression test was performed twice (standard low and high dose) without any changes in cortisol levels, leading to the suspicion of a CS caused by abnormally high ACTH production. Cranioencephalic computed tomography (CT) and magnetic resonance imaging (MRI) were performed, excluding the presence of pituitary anomalies. A follow-up whole-body CT scan was performed, revealing a suspicious pulmonary mass in the left lower lobe, associated with ipsilateral hilar lymphadenopathy and hepatic and adrenal gland lesions suggestive of secondary involvement. An endobronchial ultrasound bronchoscopy and biopsy were performed, documenting anatomopathological findings of small-cell lung carcinoma with a Ki67 expression of 100% (Figures 13).

Pulmonary-mass-(SCLC)-in-the-left-lower-lobe-with-ipsilateral-hilar-lymphadenopathy-and-pleural-effusion.
Figure 1: Pulmonary mass (SCLC) in the left lower lobe with ipsilateral hilar lymphadenopathy and pleural effusion.

SCLC: small-cell lung cancer.

Secondary-involvement-of-the-liver-with-hypodense-multilobar-hepatic-lesions-(arterial-phase).
Figure 2: Secondary involvement of the liver with hypodense multilobar hepatic lesions (arterial phase).
Bilateral-suprarenal-lesions-suggestive-of-secondary-involvement.
Figure 3: Bilateral suprarenal lesions suggestive of secondary involvement.

The patient was referred to oncology, and chemotherapy was deferred, considering the infectious risk associated with hypercortisolism.

The patient started metyrapone 500 mg every eight hours, resulting in a reduction in cortisol levels and control of hypokalemia. Later on, a fluorodeoxyglucose-positron emission tomography (FDG-PET) scan was performed, confirming disseminated disease with additional bone involvement. Unfortunately, despite endocrinological stabilization, the patient’s condition worsened, and she ended up dying one month after the diagnosis.

Discussion

When this patient was admitted, it was assumed that the metabolic alkalosis and various electrolyte disturbances were related to the gastrointestinal presentation and hyperlactatemia secondary to metformin overdose. However, the unusual persistence and refractory hypokalaemia raised some concerns that an alternative etiology might be involved and incited subsequent testing.

The high cortisol levels were unexpected given the subclinical presentation, which seems to be more frequent in cases of EAS. In fact, because of this, the true incidence of EAS is unknown and probably underdiagnosed since patients often have subclinical presentations and do not exhibit catabolic features.

Since the patient wasn’t on any steroid medication, the association between the high cortisol and ACTH levels, non-responsive to the dexamethasone suppression test, along with the absence of a pituitary lesion, raised suspicion of a probable EAS, which was later confirmed by the body CT scan and endobronchial ultrasound (EBUS).

EAS is a rare disease with a poor prognosis. It reportedly occurs in 3.2 to 6% of neuroendocrine neoplasms, and the tumor often originates in the lung, thyroid, stomach, and pancreas. Locoregional and/or distant metastasis can be seen at the time of diagnosis in 15% of typical carcinoids and about half of atypical carcinoids with visible primaries [6,7].

The presence of a typical CS presentation, with or without electrolyte abnormalities, should raise suspicion and serum levels of both ACTH and cortisol should be assessed to determine if they are elevated and to distinguish between an ACTH-dependent (pituitary or nonpituitary ACTH-secreting tumor) and an independent mechanism (e.g., from an adrenal source). The diagnosis of CS is established when at least two different first-line tests are unequivocally abnormal and cannot be explained by any other conditions that cause physiologic hypercortisolism. Additional evaluation is performed to rule out a pituitary origin (with brain MRI) and to assess for a possible ectopic ACTH-secreting tumor.

In the aforementioned case, the production of ACTH was caused by primary neuroendocrine SCLC. The recommended approach to EAS involves the initial normalization of serum cortisol levels and the treatment of related comorbidities before performing a complete diagnostic evaluation and addressing the underlying cause [5-7]. This approach seems to improve survival and prevent complications such as sepsis following a combined steroid-induced immunosuppression and chemotherapy-induced agranulocytosis [6,7].

Direct therapies vary according to the tumor, but surgery is usually the first line of treatment (transsphenoidal surgery in cases of CD or tumor resection in cases of non-metastatic EAS). However, our patient presented with stage IV SCLC with EAS, in which chemotherapy remains the first-line treatment. SCLC patients with EAS have a poorer prognosis than those without EAS, with a life expectancy of only three to six months. This makes early diagnosis more important [2,7], as controlling the high cortisol levels and then administering systemic chemotherapy may achieve longer survival [8].

Apart from systemic chemotherapy, ketoconazole (widely accepted but highly toxic), metyrapone, mitotane (adrenocortical suppressant drug with significant side effects), and mifepristone (glucocorticoid antagonist, mainly used for the treatment of hyperglycemia in CS) can be used to reduce circulating glucocorticoids. Moreover, thromboprophylaxis and Pneumocystis jirovecii pneumonia prophylaxis should be started.

Because ketoconazole may increase the risk of chemotherapy toxicity by inhibiting cytochrome P450 3A4, metyrapone has been reported to be a better choice [5,7].

Nonetheless, administration of chemotherapy in the setting of a hypercortisolism-induced immunosuppressive state, cancerous background and metabolic disorders featuring electrolyte disturbance and hyperglycemia, aggravate the condition and can be life-threatening. Thus, a palliative approach can sometimes be reasonable.

Conclusions

The diagnosis of CS is a three-step process that includes its suspicion based on the patient’s laboratory and semiologic findings, the documentation of hypercortisolism, and the identification of its cause, which can be either ACTH-dependent or independent.

The ectopic secretion of ACTH (EAS) by nonpituitary tumors is a relatively rare cause of CS and often presents as paraneoplastic syndromes, adding therapeutic and prognostic concerns.

This case, in particular, highlights the importance of seeking alternative explanations for common electrolyte disturbances, particularly when they don’t resolve promptly. Clinicians should be aware of EAS and its frequent subclinical presentation in order to initiate the diagnostic workup as soon as suspicion arises.

References

  1. Hayes AR, Grossman AB: The ectopic adrenocorticotropic hormone syndrome: rarely easy, always challenging. Endocrinol Metab Clin North Am. 2018, 47:409-25. 10.1016/j.ecl.2018.01.005
  2. Ilias I, Torpy DJ, Pacak K, Mullen N, Wesley RA, Nieman LK: Cushing’s syndrome due to ectopic corticotropin secretion: twenty years’ experience at the National Institutes of Health. J Clin Endocrinol Metab. 2005, 90:4955-62. 10.1210/jc.2004-2527
  3. Lacroix A, Feelders RA, Stratakis CA, Nieman LK: Cushing’s syndrome. Lancet. 2015, 29:913-27. 10.1016/S0140-6736(14)61375-1
  4. Nieman LK: Molecular derangements and the diagnosis of ACTH-dependent Cushing’s syndrome. Endocr Rev. 2022, 43:852-77. 10.1210/endrev/bnab046
  5. Nieman LK, Biller BM, Findling JW, Murad MH, Newell-Price J, Savage MO, Tabarin A: Treatment of Cushing’s syndrome: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2015, 100:2807-31. 10.1210/jc.2015-1818
  6. Bostan H, Duger H, Akhanli P, et al.: Cushing’s syndrome due to adrenocorticotropic hormone-secreting metastatic neuroendocrine tumor of unknown primary origin: a case report and literature review. Hormones (Athens). 2022, 21:147-54. 10.1007/s42000-021-00316-z
  7. Richa CG, Saad KJ, Halabi GH, Gharios EM, Nasr FL, Merheb MT: Case-series of paraneoplastic Cushing syndrome in small-cell lung cancer. Endocrinol Diabetes Metab Case Rep. 2018, 2018:4. 10.1530/EDM-18-0004
  8. Zhang HY, Zhao J: Ectopic Cushing syndrome in small cell lung cancer: a case report and literature review. Thorac Cancer. 2017, 8:114-7. 10.1111/1759-7714.12403

From https://www.cureus.com/articles/198133-adrenocorticotropin-dependent-ectopic-cushings-syndrome-a-case-report#!/

Interpetrosal Sphingosine-1-Phosphate Ratio Predicting Cushing’s Disease Tumor Laterality and Remission After Surgery

Background: Cushing’s disease (CD) poses significant challenges in its treatment due to the lack of reliable biomarkers for predicting tumor localization or postoperative clinical outcomes. Sphingosine-1-phosphate (S1P) has been shown to increase cortisol biosynthesis and is regulated by adrenocorticotropic hormone (ACTH).

Methods: We employed bilateral inferior petrosal sinus sampling (BIPSS), which is considered the gold standard for diagnosing pituitary sources of CD, to obtain blood samples and explore the clinical predictive value of the S1P concentration ratio in determining tumor laterality and postoperative remission. We evaluated 50 samples from 25 patients who underwent BIPSS to measure S1P levels in the inferior petrosal sinuses bilaterally.

Results: Serum S1P levels in patients with CD were significantly higher on the adenoma side of the inferior petrosal sinus than on the nonadenoma side (397.7 ± 15.4 vs. 261.9 ± 14.88; P < 0.05). The accuracy of diagnosing tumor laterality with the interpetrosal S1P and ACTH ratios and the combination of the two was 64%, 56% and 73%, respectively. The receiver operating characteristic curve analysis revealed that the combination of interpetrosal S1P and ACTH ratios, as a predictor of tumor laterality, exhibited a sensitivity of 81.82% and a specificity of 75%, with an area under the curve value of 84.09%. Moreover, we observed that a high interpetrosal S1P ratio was associated with nonremission after surgery. Correlation analyses demonstrated that the interpetrosal S1P ratio was associated with preoperative follicle-stimulating hormone (FSH), luteinizing hormone (LH), and postoperative ACTH 8 am levels (P < 0.05).

Conclusion: Our study demonstrated a significant association between the interpetrosal S1P ratio and tumor laterality, as well as postoperative remission in CD, suggesting that the interpetrosal S1P ratio could serve as a valuable biomarker in clinical practice.

1 Introduction

Cushing’s disease (CD), also known as adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma, arises from the pituitary corticotroph cells and induces endogenous hypercortisolism by stimulating the adrenal glands to produce excessive amount of cortisol (1). Patients with CD typically exhibit symptoms of hypercortisolism, such as hypertension, diabetes, purplish skin striae, mental disturbances, hyposexuality, hirsutism, menstrual disorders, acne, fatigue, obesity, and osteoporosis (1). The overall mortality of patients with CD is twice that of the general population, and if left untreated, hypercortisolism resulting from CD increases this rate to approximately four times the expected value (24). Transsphenoidal surgery continues to be the primary treatment for CD (5). However, previous studies reported variable remission rates, ranging from 45% to 95% (68). Long-term follow-up data have revealed recurrence in 3–66% of patients who had initially achieved complete remission (910). The rate of surgical remission in CD can be influenced by various factors, including the size and location of the tumor, expertise of the neurosurgeon, and criteria used for assessing remission (11). Preoperative clinical variables, such as age, gender, disease duration, and severity of clinical signs and symptoms, cannot reliably identify patients at a higher risk of nonremission (1213). Therefore, predicting postsurgical remission in CD remains a challenging goal.

Accumulating evidence has shown that sphingosine-1-phosphate (S1P), an intracellular pleiotropic bioactive sphingolipid metabolite synthesized by sphingosine kinase 1 (SPHK1), plays a pivotal role in diverse endocrine disorders (1416). Overexpression of SPHK1 promotes the progression of multiple neuroendocrine tumors (1718). ACTH can rapidly activate sphingolipid metabolism, causing an increase in S1P secretion in the adrenal cortex (19). Furthermore, the activation of S1P signaling in H295R cells, a human adrenocortical tumor cell line, has been suggested to induce increased transcription of hormone-sensitive lipase and steroidogenic acute regulatory protein, ultimately elevating cortisol production (20). Recently, surgical removal of ACTH-secreting adenoma has been reported to cause a decline in sphingomyelin levels (21). However, whether they have a similar role in the pituitary gland remains to be investigated.

Bilateral inferior petrosal sinus sampling (BIPSS) is a highly effective procedure for diagnosing pituitary sources of ACTH in CD (2223). Contemporaneous differences in ACTH concentration during venous sampling between the two sides of the adenoma can predict the location of the adenoma within the pituitary (on the side of the gland with a microadenoma) and may guide surgical treatment in cases with inconclusive magnetic resonance imaging findings. Previous studies demonstrated that an ACTH gradient of ≥1.4 between the inferior petrosal sinuses can indicate microadenoma lateralization in patients with CD (2426). However, the correct lateralization only occurs in 57–68% of all cases (2729).

Therefore, we analyzed the clinical behavior of a well-characterized cohort of patients with CD who underwent BIPSS before surgery. We measured the difference in the concentration of S1P in bilateral petrosal sinus blood samples and explored the clinical predictive value of the S1P concentration ratio in determining tumor laterality and postoperative remission.

2 Materials and methods

2.1 Patients and study design

This study was conducted at a tertiary center, involving a cohort of 25 patients diagnosed with CD who had undergone BIPSS and surgery, with a minimum follow-up duration of 2 years. Comprehensive chart reviews were conducted to collect data on demographics, clinical characteristics, pituitary imaging findings, tumor pathology, and biochemical tests.

The criteria used for diagnosing CD encompassed the presence of characteristic signs and symptoms of hypercortisolism, along with biochemical evaluation of two urinary free cortisol measurements exceeding the normal range for the respective assay, serum cortisol level >1.8 μg/dL (50 nmol/L) after an overnight 1-mg dexamethasone suppression test, and two late-night salivary cortisol measurements exceeding the normal range for the respective assay (30). A diagnosis of Cushing’s syndrome was established if the patient had positive test results for at least two of the three aforementioned tests. Adrenal insufficiency was diagnosed if patients exhibited symptoms or signs of adrenal insufficiency or if serum cortisol levels were ≤3 μg/dL, even in the absence of clinical signs or symptoms. Remission was defined as normalization of the levels of 24-h urinary free cortisol, late-night salivary cortisol, and overnight 1-mg dexamethasone suppression test in patients without concurrent central adrenal insufficiency after surgery (31).

2.2 Patients and tissue/serum samples

Surgical specimens of CD-affected tissues were collected from Xiangya Hospital, Central South University. Three normal pituitary tissues were obtained from cadaveric organ donors without any history of endocrine disease (Central South University). A total of 25 CD tissue samples were obtained for immunohistochemistry analysis. This study was conducted in compliance with the Helsinki Declaration and was ethically approved by the Xiangya Hospital Ethics Committee, Xiangya Hospital (Changsha, China). Tumor samples and corresponding clinical materials were obtained with written consent from all patients.

2.3 BIPSS

After obtaining informed consent, BIPSS was performed using standard techniques described in previous studies (3233). Briefly, the patient’s head was immobilized to ensure midline positioning and prevent any potential bias towards asymmetric pituitary drainage by the petrosal sinuses. After placing peripheral catheters and cannulating both inferior petrosal sinuses, blood samples were collected at baseline and at 3, 5, 10, and 15 min following intravenous administration of DDAVP, which stimulates pituitary production of ACTH. Additional samples for experimental purposes were collected immediately following the 15-min sample collection to avoid interference with the patient’s diagnostic study.

2.4 Measurement of baseline plasma S1P concentration

Blood samples were obtained from both petrosal sinuses and were centrifuged to remove cellular components. Samples that exhibited hemolysis or coagulation were excluded from the study. Plasma samples were stored at −80°C. The S1P levels in plasma were analyzed using a S1P competitive ELISA kit (Echelon Biosciences, Salt Lake City, UT) according to the manufacturer’s instructions (34).

2.5 Immunofluorescence staining

The pituitary tissues were post-fixed and dehydrated with alcohol as follows: 70% for 24 h, 80% for 3 h, 90% for 4 h, 95% for 3 h, and finally in absolute alcohol for 2 h. Tissue slices with a 5-μm thickness were cut using a microtome (Thermo Fisher Scientific), blocked with 3% BSA, and then treated with primary antibodies to SPHK1 (CST, #3297) and ACTH (Proteintech, CL488-66358). Subsequently, the tissue slides were incubated with Alexa Fluor 488-conjugated anti-rabbit (Invitrogen, A21206, 1:200) or Alexa Fluor 555-conjugated anti-rabbit (Invitrogen, A21428, 1:200) secondary antibodies. Specimens were visualized and imaged using a fluorescence microscope.

2.6 Statistical analysis

The Mann–Whitney U test was used to assess the clinical–molecular associations in adenoma samples, whereas the chi-square test was used to compare categorical data. The Kruskal–Wallis analysis and ANOVA were conducted for multiple comparisons. Statistical analyses were conducted using SPSS v20 and GraphPad Prism version 7. All results were presented in graphs and tables as median ± interquartile range. The distribution of each parameter was presented as the minimum–maximum range. Parametric or nonparametric statistical tests were applied, as appropriate, after testing for normality. The receiver operating characteristic curve was used to determine the cut-off value for predicting tumor laterality. Pearson correlation analyses was used to examine the correlations between variables. Proportions were expressed as percentages, and significance was defined as P < 0.05.

3 Results

3.1 Clinical characteristics of remission and nonremission in patients with CD

This study included 25 patients with CD who underwent BIPSS before surgery (Figure 1). Among them, 12 patients had microadenomas, whereas the remaining 13 had inconclusive magnetic resonance imaging findings; clinicopathological data are summarized in Supplementary Table 1Table 1 displays the demographics of patients who achieved remission (n = 16) and those who did not (n = 9). No significant differences were observed in terms of sex, age at diagnosis, or radiological variables between patients who achieved and those who did not achieve remission (P > 0.05). Patients who achieved remission exhibited a higher prevalence of emotional lability (P < 0.05). However, no significant differences were observed in other parameters (P > 0.05).

Figure 1
www.frontiersin.orgFigure 1 Flowchart of the screening process employed to select eligible participants for the study.

Table 1
www.frontiersin.orgTable 1 Baseline clinical features of patients with pituitary tumors secreting adrenocorticotropin.

Several recent studies have established morning cortisol level measured on postoperative day 1 (POD1) as a predictive biomarker for long-term remission of CD (3536). For biochemical features, patients who did not achieve remission exhibited higher serum cortisol (19.16 ± 5.55 vs. 5.95 ± 1.42; P = 0.014) and median serum (8 am) ACTH (10.26 ± 8.24 vs. 5.15 ± 3.68; P = 0.042) levels on POD1. No significant differences were observed in the preoperative baseline 4 pm serum cortisol levels, preoperative baseline 0 am serum cortisol levels, preoperative 8 pm ACTH levels, 4 pm ACTH levels, and 0 am ACTH levels (P > 0.05) (Table 2). In addition preoperative FT3, FT4, TSH, GH, FSH, LH, and PRL levels were comparable in patients with and without remission.

Table 2
www.frontiersin.orgTable 2 Baseline clinical and biochemical features of patients with pituitary tumors secreting adrenocorticotropin.

3.2 Overexpression of SPHK1 and higher concentrations of serum S1P on the tumor side in patients with CD

Prior studies have demonstrated that ACTH acutely activates SPHK1 to increase S1P concentrations (19). Upregulation of SPHK1 is associated with poor prognosis in endocrine-related cancer (171821). To investigate the role of SPHK1 in CD, we performed a heatmap analysis of key genes involved in phospholipid metabolism and signaling pathways in CD adenomas and surrounding normal tissues using the GEO dataset (GEO208107). This analysis revealed the activation of crucial genes involved in phospholipid metabolism and signaling pathways in ACTH-secreting pituitary adenomas (Supplementary Figure 1). Subsequently, we compared the association between pituitary SPHK1 expression and proopiomelanocortin, corticotropin-releasing hormone, corticotropin releasing hormone receptor 1, and corticotropin releasing hormone receptor 2 in pituitary tumor tissues and identified a positive correlation between SPHK1 and ACTH tumor-related genes in the TNM plot database (Supplementary Figure 2). To investigate the potential role of SPHK1 in CD, we compared the expression values of SPHK1 in the normal pituitary tissues and those obtained from patients with CD in the remission/nonremission groups. Immunofluorescence staining (Figures 2A, BSupplementary Figure 3) revealed an increased number of double-positive cells for SPHK1 and ACTH in CD-affected pituitary tissues than those in the normal pituitary tissues. Furthermore, the proportion of double-positive cells for SPHK1 and ACTH was significantly higher in the nonremission CD adenomas tissues than that in the remission CD adenomas. Furthermore, we investigated the concentration of S1P in bilateral petrosal sinus blood samples and observed that the concentration was significantly higher on the adenoma side than that on the nonadenoma side (397.7 ± 15.4 vs. 261.9 ± 14.88; P < 0.05, Figure 2C). Thus, these findings suggested a close association between S1P concentration and the development of ACTH-secreting tumor.

Figure 2
www.frontiersin.orgFigure 2 (A) Representative images of immunofluorescence double staining for SPHK1 (green) and ACTH (pink) in normal pituitary glands and ACTH-secreting pituitary adenomas from the remission and nonremission groups (Normal: n = 3, ACTH pituitary adenoma: remission vs. nonremission: n = 16 vs. 9); scale bars: 100-μm upper and 50-μm lower. (B) Quantitative analysis; white arrows indicate double-positive cells for ACTH and SPHK1. (C) The concentration of S1P in the plasma obtained from the inferior petrosal sinus of the adenoma side and nonadenoma side. ***P < 0.001. Bar represents mean ± SD.

3.3 Combination of interpetrosal S1P and ACTH ratios improved the diagnostic performance for adenoma laterality

The pathology of patients with CD was classified based on adenomatous tissue with ACTH-positive immunostaining into adenoma or nonadenoma sides. To evaluate the correlation between the interpetrosal S1P ratio lateralization and tumor location, we compared the accuracy of predicting tumor laterality using the interpetrosal S1P ratio (>1) and interpetrosal ACTH ratio (>1.4) (the interpetrosal ACTH ratio >1.4 is acknowledged for its positive role in predicting tumor laterality), as well as their combination. Our results indicated that using the interpetrosal S1P or ACTH ratios alone yielded accuracies of 64% and 56% respectively. Notably, the combination of both demonstrated a significantly improved accuracy of 73% (Figure 3A).

Figure 3
www.frontiersin.orgFigure 3 (A) Bar graph illustrating the accuracy of predicting tumor laterality. (B) Receiver operating characteristic (ROC) curve analysis of interpetrosal ACTH ratio to predict tumor location. (C) ROC curve analysis of the interpetrosal S1P ratio to predict tumor location. (D) ROC curve analysis of the combination of the interpetrosal S1P and ACTH ratios to predict tumor location.

Thereafter, the receiver operating characteristic analysis was performed to determine the role of predicting tumor laterality. In particular, the interpetrosal ACTH ratio with an AUC of 75.32% (95% CI: 60.06–97.46%, P < 0.05) and the interpetrosal S1P ratio demonstrated a clinically significant diagnostic accuracy for lateralization, with an AUC of 79.17% (95% CI: 44.40–85.84%, P < 0.05). Furthermore, combining the interpetrosal S1P and ACTH ratios generated an receiver operating characteristic curve with an AUC of 84.09% (95% CI: 52.3–96.77%, P < 0.05) for predicting lateralization with tumor location (cutoff value: interpetrosal S1P ratio ≥1.06, interpetrosal ACTH ratio ≥2.8, 81.82% sensitivity, and 75% specificity) (Figures 3B–D).

3.4 Interpetrosal S1P ratio serves as a predictive factor for early remission in CD

To investigate whether the interpetrosal S1P ratio is associated with early postoperative remission in CD, we compared the baseline interpetrosal S1P ratio between patients with CD in the remission and nonremission groups. Interestingly, we observed that the nonremission group exhibited higher interpetrosal S1P ratios than those of the remission group (median, 1.28 ± 0.25 vs. 1.10 ± 0.09, P = 0.012) (Figure 4).

Figure 4
www.frontiersin.orgFigure 4 Left picture: Scatter plot of bilateral S1P concentrations in the remission and nonremission groups; the slope represents the interpetrosal S1P ratio, blue dots represent the remission group, and red dots represent the nonremission group. Right picture: The interpetrosal S1P ratio in the remission and nonremission groups. *P < 0.05. Bar represents mean ± SD.

To investigate potential factors affecting the interpetrosal S1P ratio, we compared the correlation between interpetrosal S1P ratio and various clinical indicators. This analysis revealed that the interpetrosal S1P ratio positively correlated with preoperative FSH and LH levels, as well as with postoperative 8 am ACTH levels. No significant difference was observed between the interpetrosal S1P ratio and other indicators (Supplementary Figure 4).

4 Discussion

The use of BIPSS involves collection of samples from each inferior petrosal sinus simultaneously, enabling a direct comparison of ACTH concentrations between the left and right petrosal sinuses. BIPSS is used for two purposes: 1) to assist in the differential diagnosis of Cushing’s syndrome; and 2) to determine which side of the pituitary gland contains an adenoma in patients with CD. The interpetrosal ACTH ratio is also useful in determining the location/lateralization of pituitary microadenomas (243037), thereby providing guidance to the neurosurgeon during surgery.

To our knowledge, this is the first study to demonstrate that serum S1P levels in patients with CD are significantly higher on the adenoma side of the inferior petrosal sinus than on the nonadenoma side. The interpetrosal S1P ratio exhibited a positive significance in predicting tumor laterality, and the predictive performance was improved when S1P was combined with the interpetrosal ACTH ratio. Notably, the interpetrosal S1P ratio exhibited a positive significance in predicting remission after surgery. Furthermore, the interpetrosal S1P ratio demonstrated a positive and significant correlation with preoperative FSH and LH levels, as well as 8 am ACTH levels on POD1.

ACTH is recognized for its role in controlling the expression of genes involved in steroid production and cortisol synthesis in the human adrenal cortex through sphingolipid metabolism (19). Specifically, ACTH rapidly stimulates SPHK1 activity, leading to an increased in S1P levels, which in turn, increases the expression of multiple steroidogenic proteins (20). Our study demonstrated that higher S1P concentrations were present on the tumor side than on the nontumor side in patients with CD, indicating that the regulatory relationship between ACTH and S1P also exists in ACTH-secreting pituitary adenomas. Several pieces of evidence have supported the potential relationship between S1P and the occurrence of CD. Interestingly, SPHK1 and S1P are known to be integral to the regulation of epidermal growth factor receptor (EGFR) (38), which is highly expressed in human corticotropinomas, where it triggers proopiomelanocortin (the precursor of ACTH) transcription and ACTH synthesis (39). Blocking EGFR activity with an EGFR inhibitor can attenuate corticotroph tumor cell proliferation (40). Furthermore, SPHK1 and proopiomelanocortin share a common transcriptional coactivator, P300 (4142). Notably, S1P also directly binds to and inhibits histone deacetylase 2, thereby regulating histone acetylation and gene expression (43). Notably, histone deacetylase 2 expression is deficient in ACTH-pituitary adenomas in CD, contributing to glucocorticoid insensitivity (44), which is a hallmark of CD and a feature associated with nonremission. These studies further demonstrated an association between high S1P ratio and nonremission of CD. Our study, for the first time, established an association between SPHK1/S1P and ACTH adenoma. Nevertheless, further experimental verification is required to confirm the existence of common pathways linking SPHK1 and ACTH. Thus, these findings indicated that the S1P ratio can, to some extent, reflect the differences in ACTH levels and may serve as a surrogate marker for detecting ACTH-secreting pituitary adenomas.

BIPSS is a highly effective procedure for diagnosing pituitary sources of ACTH in CD and remains the gold standard diagnostic method. However, some findings indicated certain limitations associated with the use of the inferior petrosal sinus sampling (IPSS) method in predicting tumor lateralization. The possible causes of error include asymmetrical or underdeveloped petrosal sinus anatomy and placement of the catheter (27). The present study revealed a notable increase in the interpetrosal ACTH ratio among patients with accurate predictions of tumor laterality than among those with inaccurate predictions, although the positive predictive value remained low. These findings suggested that other mechanisms may exist that contribute to false-positive results. The limitations on lateralization highlighted the need for further research to understand the underlying mechanisms contributing to the accuracy of IPSS in predicting tumor lateralization. Further investigation is required to understand these potential mechanisms and improve the accuracy of IPSS in predicting tumor lateralization.

We observed that the interpetrosal S1P ratio was slightly more effective than the ACTH ratio in predicting tumor laterality. However, combining both methods significantly improved the diagnostic sensitivity and specificity. These results have important implications for clinical practice as accurate tumor lateralization is essential for the correct management and treatment of pituitary adenomas. Overall, these findings highlighted the importance of using multiple measures in predicting tumor lateralization and suggested that combining measures may be more effective than relying on any single measure alone. Future research should investigate additional measures to improve the accuracy of tumor lateralization and optimize the use of existing measures for making clinical decisions.

The initial treatment recommendation for CD is surgery. However, long-term surveillance is necessary because of the high recurrence rate (12). Therefore, identifying patients who are at a greater recurrence risk would be helpful in establishing an effective surveillance strategy. Our study revealed that the expression of SPHK1 in pituitary tissue was higher in postoperative nonremission group than in postoperative remission group. Moreover, patients in the nonremission group exhibited significantly higher interpetrosal S1P ratios than those of patients in the remission group. SPHK1 catalyzes the direct phosphorylation synthesis of S1P, and the S1P ratio can thus reflect the expression level of SPHK1 in ACTH tumors. Since S1P can increase the expression of multiple steroidogenic proteins, including steroidogenic acute regulatory protein, 18-kDa translocator protein, low-density lipoprotein receptor, and scavenger receptor class B type I (20), the interpetrosal S1P ratios may be indicative of disease prognosis. This finding is consistent with previous findings indicating the overexpression of SPHK1 is associated with poor prognosis in various neuroendocrine tumors, as factors associated with tumor proliferation, S1P and SPHK1, may play a key role in the proliferation and survival of ACTH pituitary adenomas. The high proportions of SPHK1/ACTH double-positive cells are likely associated with greater phenotypic severity, and CD tumors with this phenotype may have a poor prognosis. These findings hold clinically significance for predicting early postoperative remission in patients with CD. As aforementioned, the interpetrosal S1P ratios have been suggested as a useful diagnostic tool for determining adenoma lateralization in CD, which can also serve as a prognostic indicator for postoperative remission.

Pearson correlation analysis indicated that ACTH 8 am on POD1 and FSH/LH levels were significantly associated with the interpetrosal S1P ratio, suggesting that these pituitary dysfunctions may have a role in the early remission of CD. However, the sample size in this study was relatively small, and further studies with larger sample sizes are needed to confirm these findings. Additionally, other factors affecting surgical outcomes, such as the experience of the surgeon, extent of surgical resection, and use of adjuvant therapy, should be considered when predicting postoperative remission in patients with CD.

This study has some limitations. First, the study was retrospective in design, which limited the control of confounding factors. Additionally, because of the limited sample size, we did not specifically investigate cases where the ACTH ratio failed to accurately identify the correct tumor location. Finally, we did not explore the functional evidence of a common pathway between SPHK1 and ACTH. Despite these limitations, the study contributes to our understanding of the potential utility of the interpetrosal S1P ratio as a biomarker for CD and provides a basis for future research in this area.

In conclusion, our study demonstrated a significant association between the interpetrosal S1P ratio and tumor laterality, as well as in early remission in CD. These findings suggested that the interpetrosal S1P ratio could serve as a useful biomarker in clinical practice. Moreover, targeting genes and drugs related to SPHK1/S1P could provide novel therapeutic strategies for treating CD.

Data availability statement

The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.

Ethics statement

The studies involving humans were approved by The Xiangya Hospital Ethics Committee, Xiangya Hospital (Changsha, China). The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.

Author contributions

HS: conceptualization, methodology, software, visualization, and investigation. CW and BH: software. YX: writing – review & editing. All authors contributed to the article and approved the submitted version.

Funding

The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.

Acknowledgments

The authors gratefully acknowledge contributions from the GEO databases and TNMplot database (https://www.tnmplot.com/).

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fendo.2023.1238573/full#supplementary-material

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Keywords: ipss, sphingosine-1-phosphate, Cushing’s disease, remission, tumor laterality

Citation: Sun H, Wu C, Hu B and Xiao Y (2023) Interpetrosal sphingosine-1-phosphate ratio predicting Cushing’s disease tumor laterality and remission after surgery. Front. Endocrinol. 14:1238573. doi: 10.3389/fendo.2023.1238573

Received: 12 June 2023; Accepted: 17 October 2023;
Published: 31 October 2023.

Edited by:

Anton Luger, Medical University of Vienna, Austria

Reviewed by:

Guangwei Wang, Hunan University of Medicine, China
Marie Helene Schernthaner-Reiter, Medical University of Vienna, Austria

Copyright © 2023 Sun, Wu, Hu and Xiao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Yuan Xiao, xiaoyuan2021@csu.edu.cn

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

From https://www.frontiersin.org/articles/10.3389/fendo.2023.1238573/full

Bilateral Inferior Petrosal Sinus Sampling: Validity, Diagnostic Accuracy in Lateralization of Pituitary Microadenoma, and Treatment In Eleven Patients with Cushing’s Syndrome – a Single-Center Retrospective Cohort Study

Abstract

Background

This single-center retrospective cohort study aimed to describe the findings and validity of Bilateral inferior petrosal sinus sampling (BIPSS) in the differential diagnosis of patients with ACTH-dependent Cushing’s syndrome (CS).

Methods

Eleven patients underwent BIPSS due to equivocal biochemical tests and imaging results. Blood samples were taken from the right inferior petrosal sinus (IPS), left IPS, and a peripheral vein before and after stimulation with desmopressin (DDAVP). ACTH and prolactin levels were measured. The diagnosis was based on the ACTH ratio between the IPS and the peripheral vein. Also, lateralization of pituitary adenoma in patients with Cushing’s disease (CD) was predicted. No significant complications were observed with BIPSS.

Results

Based on the pathology report, eight patients had CD, and three had ectopic ACTH syndrome (EAS). Unstimulated BIPSS resulted in a sensitivity of 87.5%, specificity of 100%, PPV of 100%, NPV of 75%, and accuracy of 91%. Stimulated BIPSS resulted in a sensitivity of 100%, specificity of 100%, PPV of 100%, NPV of 100%, and accuracy of 100%. However, pituitary magnetic resonance imaging (MRI) had a lower diagnostic accuracy (sensitivity:62.5%, specificity:33%, PPV:71%, NPV:25%, accuracy:54%). BIPSS accurately demonstrated pituitary adenoma lateralization in 75% of patients with CD.

Conclusions

This study suggests that BIPSS may be a reliable and low-complication technique in evaluating patients with ACTH-dependent CS who had inconclusive imaging and biochemical test results. The diagnostic accuracy is improved by DDAVP stimulation. Pituitary adenoma lateralization can be predicted with the aid of BIPSS.

Peer Review reports

Introduction

All disorders with manifestations associated with glucocorticoid excess are called Cushing’s syndrome. Exogenous corticosteroids cause most CS cases, and endogenous CS cases are rare [12].

The diagnosis of Cushing’s syndrome may be complicated, particularly in cases with ambiguous clinical findings, atypical presentations, and cyclic hypercortisolemia [3,4,5]. The initial laboratory tests for diagnosis of CS include 24-hour urinary free cortisol (UFC), late-night salivary cortisol, and low-dose dexamethasone suppression test (DST). These tests only represent hypercortisolemia [12].

Once CS is diagnosed, further evaluations are needed to identify the etiology. The first step is to measure the plasma ACTH level. A low plasma ACTH level indicates ACTH-independent CS and a high level suggests ACTH-dependent CS. Normal ACTH can also occur in ACTH-dependent CS. Almost all cases of ACTH-dependent are due to pituitary adenoma (Cushing’s disease) or EAS [126].

Some ectopic sources include neuroendocrine tumors, bronchial carcinoma, and pancreatic carcinoma [78]. Because of the high mortality in tumors associated with EAS, it is essential to differentiate CD from EAS.

To distinguish CD from EAS, a high-dose dexamethasone suppression test (HDDST), corticotropin-releasing hormone (CRH), or DDAVP stimulation tests, or pituitary MRI is recommended [1269,10,11,12]. MRI can be equivocal in half of the patients, and only relatively large lesions (> 6 mm) detected on MRI reliably confirm the diagnosis of CD with biochemical confirmation and expected clinical symptoms [9].

Considering the relatively low sensitivity and specificity of non-invasive tests [1314] and the high complications of the surgery, it seems reasonable to use a test with high sensitivity and specificity and few complications before resection. BIPSS with CRH or DDAVP stimulation can be helpful for further evaluation [12101516]. The BIPSS procedure is the same in both stimulation methods. Due to its lower cost, availability, and comparable diagnostic accuracy, using DDAVP instead of CRH for BIPSS is an alternative [1718]. BIPSS has been reported to have high sensitivity and specificity and is a safe procedure when performed by experienced interventional radiologists [15161920].

This case series describes the experience with BIPSS and examines the validity of BIPSS for differentiating CD from EAS in patients with ACTH-dependent CS who had ambiguous or equivocal results in non-invasive tests.

Materials and methods

Patients

This retrospective cohort study included 11 patients with ACTH-dependent CS who underwent BIPSS between 2018 and 2020 in a tertiary care hospital.

Data collection

Well-trained nurses conducted anthropometric measurements, including height and weight. Standing height was measured with a portable stadiometer (rounded to the nearest 0.1 cm). Using a calibrated balance beam scale, this study measured weight in the upright position (rounded to the nearest 0.1 kg). Body mass index (BMI) was calculated by dividing weight (kg) by height squared (m2). Well-trained examiners measured blood pressure (systolic and diastolic) at the left arm in the sitting position after 5 min of rest using a calibrated mercury sphygmomanometer. The blood sample was taken, and fasting blood sugar (FBS), hemoglobin (Hb), potassium (K), and creatinine (Cr) were measured. All research was performed in accordance with the Declaration of Helsinki. Informed consent was obtained from all participants or their legal guardians.

Biochemical tests and imaging

Patients with signs and symptoms of CS underwent screening evaluations, and confirmatory tests were performed using serum cortisol and 24-hour UFC. After confirmation of CS, ACTH was measured using an immunoradiometric assay to categorize patients into ACTH-dependent or independent groups. ACTH test was performed with SIEMENS IMMULITE 2000 device with an analytical sensitivity of 5 pg/ml (1.1 pmol/l) and CV ∼7.5%. HDDST was conducted by administering 2 mg dexamethasone every 6 h for 48 h to all patients, and then serum cortisol and 24-hour UFC were rechecked. A pituitary MRI was performed with sagittal and coronal T1- and T2-weighted images before and after the gadolinium injection.

BIPSS procedure

After biochemical tests and imaging, an experienced interventional radiologist performed bilateral and simultaneous catheterization of the inferior petrosal sinuses. Venography was obtained to evaluate venous anatomy and catheter placement. The retrograde flow of contrast dye into the contralateral cavernous sinuses was used as a marker of adequate sampling. After the correct placement of catheters, blood samples were obtained from each of three ports (peripheral (P), left inferior petrosal sinus (IPS), and right IPS) at -15, -10, -5, and 0 min. The current study used DDAVP for stimulation. After peripheral injection of 10 micrograms of DDAVP, blood samples from these three sites were obtained at + 3, +5, + 10, and + 15 min. Three samples from these sites were also obtained to measure prolactin. Upon collection, BIPSS samples were placed in an ice-water bath. At the end of the procedure, samples were taken to the laboratory, where the plasma was separated and used for immediate measurement of ACTH. Specimens were refrigerated, centrifuged, frozen, and assayed within 24 h.

After the samples were obtained, both femoral sheaths were removed, and manual compression was used to obtain hemostasis before transferring patients to the recovery room. The whole procedure took 1–2 h. Patients underwent strict bed rest for 4 h before discharge on the same day. All BIPSS were performed without significant complications, and only hematoma at the catheterization site was observed in some patients.

BIPSS interpretation

The ratio of IPS ACTH to peripheral ACTH level (IPS/P ACTH) for each side was calculated. Baseline sampling at minute 0 with IPS/P ≥ 2 or stimulated sampling at minute 3 with 1PS/P ≥ 3 is confirmatory for CD [18]. Also, the IPS/P ratio was checked for prolactin level after DDAVP stimulation (stimulated IPS/P prolactin). A stimulated IPS/P prolactin ≥ 1.8 indicates successful catheterization, meaning the catheter is correctly placed in the IPS [21]. For further evaluation, the current study normalized the ACTH to the prolactin level by dividing stimulated IPS/P ACTH into stimulated IPS/P prolactin for each side. A normalized ACTH/prolactin IPS/P ratio ≥ 1.3 supports a pituitary ACTH source (Cushing’s disease), and a normalized ratio ≤ 0.7 an ectopic source (EAS) [22]. The values between 0.7 and 1.3 are equivocal. The inter-sinus ratio was defined as the ratio of the IPS/P ACTH level of one side with the higher level divided by the IPS/P ACTH level of the other side with the lower level, either before or after stimulation. An inter-sinus ratio ≥ 1.4 indicates lateralization to the side with a higher IPS/P ACTH level [23].

Statistical analysis

This analysis used SPSS software version 18 (SPSS, Inc.) to perform analyses. Data were expressed as numbers and percentages. Continuous variables were presented as means (± SD). This study reported the median or range when the data did not follow a normal distribution. The Shapiro-Wilk test was used to test for normality. The nonparametric Mann-Whitney U Test was utilized to compare variables. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the tests were calculated based on standard statistical equations.

Results

Baseline characteristics and clinical manifestations

This retrospective research studied 11 patients with ACTH-dependent CS, including eight females (72.7%) and three (27.3%) males. The median (Q1-Q3) age was 32.0 (22–45) years. The median (Q1-Q3) of BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP), FBS, Hb, K, and Cr were 29.2 (24.8–33.3), 130.0 (125–140), 80.0 (80–95), 98.0 (88–103), 13.5 (12.4–13.9), 4.2 (3.9–4.5), and 1.0 (0.9–1.1), respectively. The demographic characteristics of patients are presented in Table 1. The Hb levels were not different in women and men (median 13.35 vs. 13.70, p-value = 0.776). In addition, no statistical difference between patients with a final diagnosis of CD and EAS was detected for Hb levels (Total: median 13.60 vs. 13.2, p-value > 0.05) (Women: median 13.5 vs. 13.2, p-value > 0.05) (Men: median 13.7 vs. 13.25, p-value > 0.05).

Table 1 Demographic characteristics of the studied patients

90% of patients had at least one skin manifestation, such as striae, easy bruising, acne, hyperpigmentation, hirsutism, hair loss, edema, and hypertrichosis. Other symptoms were hypertension (HTN) (81%), reproductive dysfunction (81%), including infertility, oligomenorrhea, loss of libido, weight gain (72%), proximal muscle weakness (45%), and headache (27%) (Table 2).

Table 2 Clinical manifestations of the studied patients

Results of biochemical tests

Biochemical tests results, including basal serum cortisol (median:26 mcg/dl, range:15-54.5 mcg/dl), basal 24-hour UFC (median:670 mcg/dl, range:422–1545 mcg/dl), ACTH (median:58.8 pg/ml, range:25–155 pg/ml), serum cortisol after HDDST (median:14.2 mcg/dl, range:2.63-36.0 mcg/dl), 24-hour UFC after HDDST (median:292 mcg/dl, range:29.5–581 mcg/dl) are presented in Table 3. According to the basal serum cortisol results, eight patients (Cases 1, 3, 5, 7, 8, 9, 10, and 11) had basal serum cortisol levels > 22 mcg/dl, which indicates hypercortisolemia. Other patients (Cases 2, 4, and 6) had basal serum cortisol in the normal range (5–25 mcg/dl) and were considered as false negative results of this test.

Table 3 The results of biochemical tests in the studied patients

All patients had elevated basal 24-hour UFC levels (422–1545 mcg/dl), indicative of hypercortisolemia (Table 3).

There were six patients with elevated peripheral ACTH levels (> 58 pg/ml) (cases 5, 6, 8, 9, 10, and 11). Other patients had ACTH within the normal range (6–58 pg/ml) (cases 1, 2, 3, 4, 7) (Table 3).

None of the patients showed suppression after 1 mg DST. After HDDST, cases 2, 3, 8, and 10 had more than 50% suppression of serum cortisol. In the other six patients, serum cortisol was not suppressed or suppressed by less than 50%. In one patient, serum cortisol levels were not measured (case 1) because the sample was not stored under standard test conditions.

Also, eight patients had more than 50% 24-hour UFC suppression after HDDST (cases 1, 2, 3, 4, 6, 7, 9, and 10). In two patients, 24-hour UFC was suppressed less than 50% (cases 5 and 11), and in one patient (case 8), the 24-hour UFC sample was not tested due to the non-standard condition of the sample.

BIPSS results

BIPSS results before and after stimulation are shown in Table 4. The baseline value (sampling at minute 0) of IPS/P ACTH ≥ 2 confirms CD. According to this ratio, cases 1,3,4,5,6,7, and 8 were diagnosed as CD. The unilateral source for CD was confirmed in cases 1, 3, 7, and 8. BIPPS didn’t demonstrate lateralization in cases 4, 5, and 6.

Table 4 Baseline and stimulated IPS/P ratio for ACTH and Prolactin in the studied patients

The highest IPS/P ACTH ratio was 3 min after the DDAVP injection. A sampling at minute 3 with stimulated IPS/P ACTH ≥ 3 confirms CD. This ratio confirmed CD in cases 1–8 and showed a unilateral source for CD in cases 1, 2, 3, and 7. The ratio didn’t demonstrate lateralization in cases 4, 5, 6, and 8. The stimulated IPS/P prolactin was ≥ 1.8 in all cases.

The variability in the IPS/P ACTH ratio in patients with CD is shown in Fig. 1. The peak of this ratio was 3 min after the DDAVP injection. In patients with EAS, there were no changes before or after the DDAVP stimulation.

Fig. 1

figure 1

Comparison of mean values of IPS/P ACTH in CD (Lt.) and EAS (Rt.). IPS; inferior petrosal sinus; P: peripheral; ACTH: adrenocorticotropic hormone; CD: Cushing’s disease; EAS: ectopic ACTH syndrome; Lt: left; Rt: right

According to the Prolactin-normalized ACTH IPS/P ratios, eight patients (cases 1–8) were diagnosed as CD and three as EAS (cases 9–11). In cases 1, 2, 3, 7, and 8, unilateral sources of CD were confirmed, but in cases 4,5 and 6, bilateral sources were detected (Table 4).

According to the inter-sinus ratio, BIPSS could lateralize the source of ACTH in all patients with CD. The inter-sinus ratio in patients with EAS could not lateralize any pituitary source for ACTH (Table 4).

In five patients with CD and one with EAS, the highest peripheral ACTH level was observed 15 min after stimulation. Two patients with CD and one with EAS had the highest peripheral ACTH level 10 min after stimulation. Only one patient with CD and one with EAS had the highest peripheral ACTH level 5 min after stimulation. No patient had maximum peripheral ACTH levels in the first post-stimulation sample (minute 3).

The larger numerator or smaller denominator produces a higher value in a ratio. In the samples obtained immediately after stimulation, the highest concentration of ACTH was in the IPS, and the lowest was in the peripheral blood. Therefore, as mentioned, the highest post-stimulation value of the IPS/P ACTH ratio was obtained at minute 3.

MRI results

MRI results showed pituitary adenoma in five patients, enhancement in one patient, pituitary mass and lesion in two patients, empty sella in two patients, and possible pituitary adenoma and adrenal mass in one patient (Table 5).

Table 5 Final diagnosis, lateralization, MRI results, and management

Immunohistochemistry (IHC) results

According to the pathology report, eight patients were confirmed as CD (Table 5). The other two patients were EAS (one carcinoid tumor of the lung and one pheochromocytoma). One patient had no documented pathologic source of hypercortisolemia because the patient did not consent to surgery, and the diagnosis of EAS was made based on the results of biochemical tests.

BIPSS vs. MRI results

MRI results showed pituitary adenoma in five patients with CD. MRI and BIPSS showed the adenoma on a similar side in two of them. In the other three patients, MRI showed bilateral adenoma, but BIPSS lateralized the adenoma to one side. One of the other three patients had only left-sided enhancement but no overt adenoma on MRI, whereas BIPSS lateralized the adenoma to the right side. One patient had a low-signal pituitary mass on the right side on MRI, and BIPSS also lateralized to the right. Another patient with a history of transsphenoidal surgery (TSS), diagnosed as recurrent CD, had a partially empty sella. MRI was equivocal, but BIPSS lateralized to the left side.

Among patients with EAS, one with an equivocal BIPSS result had an empty sella on MRI. Two other patients had pituitary lesions on MRI, but BIPSS results were equivocal.

Comparison between BIPSS, MRI, and surgery

Among patients with CD, the final diagnosis based on surgery in three patients was consistent with MRI and BIPSS results and lateralized the adenoma on the same side. In one patient, the surgery result was similar to the MRI findings and showed bilateral adenoma, but BIPSS showed adenoma on the left side. In the patient with equivocal MRI findings and a history of TSS, IHC could not identify ACTH +, although BIPSS lateralized to the left side. In three other patients, surgery results were concordant with BIPSS and lateralized the adenoma on the same side, although MRI showed discordant results.

Validity of BIPSS

Baseline IPS/P ACTH resulted in a sensitivity of 87.5%, specificity of 100%, PPV of 100%, NPV of 75%, and accuracy of 91%. Stimulation with DDAVP improved validity. Both stimulated IPS/P ACTH and normalized ACTH/prolactin IPS/P ratio resulted in a sensitivity of 100%, specificity of 100%, PPV of 100%, NPV of 100%, and accuracy of 100%. BIPSS, either unstimulated or stimulated, had higher validity than MRI, with a sensitivity of 62.5%, specificity of 33%, PPV of 71%, NPV of 25%, and accuracy of 54%. BIPSS accurately predicted pituitary adenoma lateralization in 75% of patients with CD.

Discussion

In this study, BIPSS before stimulation showed a sensitivity of 87.5% and a specificity of 100%. However, BIPSS after stimulation showed a sensitivity of 100% and specificity of 100%. It has been demonstrated that the sensitivity of BIPSS can vary from 88 to 100%, and its specificity from 67 to 100% in the diagnosis of CD [24]. Previous studies have reported sensitivity and specificity of more than 80% and 90% for BIPSS, and the combination of BIPSS with stimulation by CRH or DDAVP improves the sensitivity and specificity to more than 95 and 100%, respectively [151925]. Chen et al. suggested the optimal IPS:P cutoff value of 1.4 before and 2.8 after stimulation [20]. Considering these cutoffs, the only patient in this study who was negative for CD before stimulation becomes positive, and the sensitivity before stimulation increases from 87.5 to 100%. The diagnostic accuracy after stimulation remains unchanged. Results of the current study showed that BIPSS is highly valued in final diagnosis, even without stimulation.

In this investigation, the utilization of Prolactin-normalized ACTH IPS/P ratios exhibited a sensitivity and specificity of 100% for the CD diagnosis. This finding aligns with research conducted by Detomas et al., which reported a sensitivity of 96% and specificity of 100% for the normalized ACTH: Prolactin IPS/P ratio [26]. It seems that concurrently assessing prolactin levels may potentially enhance the diagnostic accuracy of BIPSS. However, the current literature is inconsistent. Some studies do not support the use of prolactin to diagnose CD [27].

In all patients, the IPS/P ACTH ratio at minute 15 did not show a considerable difference from this ratio at minute 0. Previous studies have shown that sampling at minute 15 is not helpful for diagnosis [1152028]. Unlike the IPS/P ACTH ratio, six patients had the highest peripheral ACTH level at minute 15 after stimulation, but no patient had it at minute 3 after stimulation. However, more studies are needed to obtain more precise results, and this study’s sample size was limited.

BIPSS accurately lateralized the adenoma in six patients with CD, but MRI was able to lateralize the adenoma in two patients correctly. BIPSS had higher validity than MRI in differentiating CD from EAS, both with and without stimulation. The current literature is controversial. Colao et al. reported that adenoma could be accurately localized in 65% of patients using IPSS [23]. However, Lefournier et al. showed that the diagnostic accuracy of IPSS in identifying the side of the pituitary adenoma was 57% [28]. Wind et al. showed that the PPV for IPSS to identify the tumor side correctly was 69%. Additionally, MRI was more accurate than IPSS in tumor lateralization [29]. Earlier studies have shown that MRI may show a pituitary lesion, and BIPSS indicates a pituitary adenoma. However, the lesion observed on the MRI is not related to the pituitary adenoma [115192528]. Also, MRI may show pituitary lesions, while BIPSS indicates EAS.

In the current study, the concordance of IHC results with BIPSS and MRI findings was inconclusive, possibly due to the limited number of patients. However, there is disagreement about the role of pathological study in diagnosis [1928].

Eight patients had elevated basal serum cortisol levels in this study (Sensitivity:73%). Instead, all patients had hypercortisolemia according to basal 24-hour UFC results, and no false-negative results were observed (Sensitivity:100%). This study’s findings were consistent with previous studies regarding low sensitivity for basal serum cortisol and high sensitivity for 24-hour UFC as screening tests for hypercortisolemia [63031].

After HDDST, basal serum cortisol suppression was observed in three patients with CD (cases 2, 3, and 8) but not in the others with CD. Also, serum cortisol levels were suppressed after HDDST in a patient with EAS who had a lung carcinoid tumor. Arnaldi et al. showed that some carcinoid tumors might be sensitive to HDDST, and suppression of serum cortisol may be observed after this test [132]. After HDDST, six patients with CD had suppressed 24-hour UFC, but one did not show more than 50% suppression. Two patients with EAS had more than 50% 24-hour UFC suppression.

According to the final pathology report, the sensitivity of serum and urine cortisol level tests after HDDST was 43% and 86%, and the specificity was 67% and 33%, respectively. PPV in both was 75%, NPV was 33% and 50%, and accuracy was 50% and 70%, respectively, which shows that these preliminary tests cannot be a good guide for the final diagnosis and subsequent treatment planning. Previous studies showed that more than one biochemical test could improve the accuracy for differentiating between CD and EAS [156931]. The current study confirms the importance of using more than one biochemical test for diagnosing hypercortisolemia and diagnosing CD from EAS.

Detomas et al. reported that Hb levels were high in females with CS while they were low in males with CS. Furthermore, there were lower levels of Hb in EAS than in CD in females [33]. In the current study, the Hb levels were not different in women and men. Furthermore, no statistical difference was observed for Hb levels between patients with a final diagnosis of CD and EAS. Hb levels did not contribute to diagnosing ACTH-dependent CS in this analysis.

There were some limitations in this study. First, the sample size was relatively small. Second, it was a retrospective study. Further studies could investigate the BIPSS in a larger sample size and determine the validity of this method in patients with CS.

Conclusions

The current study suggests that BIPSS can be a reliable and low-complication method in evaluating patients with ACTH-dependent CS who had equivocal results in imaging and biochemical tests, even before stimulation. Stimulation with DDAVP increases diagnostic accuracy. BIPSS can be used to predict the lateralization of the pituitary adenoma.

Data Availability

All data generated or analyzed during this study are included in this published article.

Abbreviations

BIPSS:
Bilateral inferior petrosal sinus sampling
ACTH:
Adrenocorticotropic hormone
CS:
Cushing’s syndrome
IPS:
Inferior petrosal sinus
DDAVP:
Desmopressin
CD:
Cushing’s disease
EAS:
Ectopic ACTH syndrome
MRI:
Magnetic resonance imaging
UFC:
Urinary free cortisol
DST:
Dexamethasone suppression test
HDDST:
High-dose dexamethasone suppression test
CRH:
Corticotropin-releasing hormone
BMI:
Body mass index
FBS:
Fasting blood glucose
Hb:
Hemoglobin
Cr:
Creatinine
PPV:
Positive predictive value
NPV:
Negative predictive value
SBP:
Systolic blood pressure
DBP:
Diastolic blood pressure
K:
Potassium
HTN:
Hypertension
IHC:
Immunohistochemistry
TSS:
Transsphenoidal surgery

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Acknowledgements

The authors wish to thank the patients for their participation and kind cooperation.

Funding

The authors did not receive support from any organization for the submitted work.

Author information

Authors and Affiliations

  1. Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran

    Mohammadali Tavakoli Ardakani, Soghra Rabizadeh, Amirhossein Yadegar, Fatemeh Mohammadi, Sahar Karimpour Reyhan, Reihane Qahremani, Alireza Esteghamati & Manouchehr Nakhjavani

  2. Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran

    Hossein Ghanaati

Contributions

MN and MTA and SR: Conception and design of the study. AY and FM and HG: Acquisition of data. MTA and AY and SR: Analysis and interpretation of data. FM and RQ and SK: Drafting the article. MN and AE and AY: Critical revision of the article. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Manouchehr Nakhjavani.

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This study was performed in line with the principles of the Declaration of Helsinki. Informed consent was obtained from all participants or their legal guardians. Approval was granted by the Research Ethics Committee of Tehran University of Medical Sciences (Approval number: IR.TUMS.MEDICINE.REC.1398.707).

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In order to publish this study, written informed consent was obtained from each participant. A copy of the written consent form is available for review by the journal editor.

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Ardakani, M.T., Rabizadeh, S., Yadegar, A. et al. Bilateral inferior petrosal sinus sampling: validity, diagnostic accuracy in lateralization of pituitary microadenoma, and treatment in eleven patients with Cushing’s syndrome – a single-center retrospective cohort study. BMC Endocr Disord 23, 232 (2023). https://doi.org/10.1186/s12902-023-01495-z

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Long-Term Efficacy and Safety of Subcutaneous Pasireotide Alone or In Combination With Cabergoline in Cushing’s Disease

Objective: This study evaluated short- and long-term efficacy and safety of the second-generation somatostatin receptor ligand pasireotide alone or in combination with dopamine agonist cabergoline in patients with Cushing’s disease (CD).

Study design: This is an open-label, multicenter, non-comparative, Phase II study comprising 35-week core phase and an optional extension phase. All patients started with pasireotide, and cabergoline was added if cortisol remained elevated. Eligible patients had active CD, with or without prior surgery, were pasireotide naïve at screening or had discontinued pasireotide for reasons other than safety. Primary endpoint was proportion of patients with a mean urinary free cortisol (mUFC) level not exceeding the upper limit of normal (ULN) at week 35 with missing data imputed using last available post-baseline assessments.

Results: Of 68 patients enrolled, 26 (38.2%) received pasireotide monotherapy and 42 (61.8%) received pasireotide plus cabergoline during the core phase. Thirty-four patients (50.0%; 95% CI 37.6–62.4) achieved the primary endpoint, of whom 17 (50.0%) received pasireotide monotherapy and 17 (50.0%) received combination therapy. Proportion of patients with mUFC control remained stable during the extension phase up to week 99. Treatment with either mono or combination therapy provided sustained improvements in clinical symptoms of hypercortisolism up to week 99. Hyperglycemia and nausea (51.5% each), diarrhea (44.1%) and cholelithiasis (33.8%) were the most frequent adverse events.

Conclusion: Addition of cabergoline in patients with persistently elevated mUFC on maximum tolerated doses of pasireotide is an effective and well-tolerated long-term strategy for enhancing control of hypercortisolism in some CD patients.

Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT01915303, identifier NCT01915303.

1 Introduction

Cushing’s disease (CD) is a rare condition arising from chronic overproduction of cortisol, secondary to an adrenocorticotropic hormone (ACTH)-secreting pituitary tumor (1). Untreated hypercortisolism results in substantial multisystem morbidity, impaired quality of life (QoL) and premature mortality (14).

Pasireotide is a second-generation, multireceptor-targeted somatostatin receptor ligand (SRLs), with affinity for 4 of the 5 known somatostatin receptor subtypes (SSTRs) (5) and is approved for the treatment of patients with CD for whom surgery has failed or is not an option (6). Phase III trials of pasireotide monotherapy have shown sustained biochemical and clinical benefits up to 5 years (69). These benefits are also reflected in real-world evidence (10).

Cabergoline, a potent dopamine agonist with high affinity for dopamine type 2 receptors (D2), is commonly used off-label for the treatment of CD (2). Small, retrospective, non-randomized studies have demonstrated long-term urinary free cortisol (UFC) control (24−;60 months) in 23−;40% of patients with CD, especially those with mild hypercortisolism (1113). A meta-analysis of individual patient data from six observational studies (n=124) reported normalization of mean UFC (mUFC) levels in 34% of patients (1415). However, a short prospective study on cabergoline monotherapy showed a limited value in controlling UFC, possibly linked to short duration (16). As most corticotropinomas co­express SSTR5 and D2, combining pasireotide and cabergoline in a stepwise approach could potentially improve efficacy with achieving more rapid biochemical control (17), a premise supported by results from an 80-day pilot study of 17 patients with CD treated with cabergoline- pasireotide combination, and low-dose ketoconazole (in case of lack of complete control with the two-drug combination) (18).

The current study aims to report the efficacy and safety of prolonged treatment with pasireotide alone or in combination with cabergoline from the largest prospective, multicentre study to date of a pituitary-targeting combination treatment regimen in patients with CD (NCT01915303).

2 Materials and methods

2.1 Patients

Adults (≥18 years) with a confirmed diagnosis of CD or de novo CD, if they were not candidates for surgery or refused surgery were enrolled. Cushing’s disease was defined by a mean 24-hour (24h) UFC level greater than the upper limit of normal (ULN, 137.95 nmol/24h), calculated from three 24h samples collected within 2 weeks; a morning plasma ACTH level within or above the normal range; and a confirmed pituitary source of Cushing’s syndrome, determined by MRI confirmation of pituitary adenoma >6mm or inferior petrosal sinus sampling (IPSS) gradient >3 after CRH stimulation (or >2 if IPSS without CRH stimulation) for those patients with a tumor ≤6mm. For patients who had prior pituitary surgery, histopathology confirming an ACTH staining adenoma was considered confirmatory of CD. Key exclusion criteria included optic chiasm compression requiring surgery, poorly controlled diabetes (glycated hemoglobin [HbA1c] >8%) and having risk factors for torsades de pointes (for further details, see the Supplementary Appendix).

2.2 Study design

This was a single-arm, open-label, multicenter, non-comparative, Phase II study. After 4 weeks of screening, patients were treated in a stepwise approach during the core phase. Patients received subcutaneous pasireotide 0.6 mg twice daily (bid) for 8 weeks. Patients with a mUFC level exceeding ULN after 8 weeks received pasireotide 0.9 mg bid for another 8 weeks. If mUFC level remained elevated with pasireotide 0.9 mg bid, oral cabergoline 0.5 mg once daily (qd) was added for 8 weeks and could be increased to 1.0 mg qd for another 8 weeks (Supplementary Figure S1). After 35 weeks of treatment in the core phase, patients could enter the extension phase of the trial. Addition or titration of cabergoline during the extension phase was at the discretion of investigators.

Collection of extension data commenced from week 43, and patients continued their current study treatment up to study end (4 September 2019; date of last patient visit), week 257. Data beyond week 99 are not reported here because of small patient numbers.

2.3 End points and assessments

The primary endpoint of the study was the proportion of patients with mUFC ≤ULN at week 35. Secondary endpoints (reported at 4-week intervals up to week 35 and 8-week intervals from week 43 to the date of the last patient visit) included changes from baseline in mUFC, plasma ACTH, serum cortisol, total cholesterol, and clinical signs (systolic/diastolic blood pressure, body mass index (BMI), weight, waist circumference, facial rubor, hirsutism, striae, supraclavicular and dorsal fat pads) and symptoms (CushingQoL). Treatment escape was defined as an increase in one UFC above the normal range during follow-up of complete responders (14). Cushing Quality of Life Questionnaire (CushingQoL) (19) scores were reported up to week 35 only. Details on the safety assessments are provided in the Supplementary Appendix.

2.4 Statistical analyses

No formal hypothesis testing was performed because of the exploratory design of the study. Efficacy analyses were conducted on full analysis set, i.e., all patients to whom study treatment was assigned. Safety analyses were conducted on all patients who received ≥1 dose of pasireotide per day during the study. For patients with missing mUFC value at week 35, including those who discontinued, the last available assessment was carried forward. Details on the post hoc analyses and sample size estimation is provided in the Supplementary Appendix. Enrolled patients, who were observed for failed inclusion or exclusion criteria during the monitoring visits, were classified under protocol deviation. However, patients with no safety concerns were allowed to continue in the study and included in the full analysis set as intention to treat – assessing the study outcome, while some patients were excluded from the per protocol analysis.

3 Results

3.1 Study population

A total of 68 patients were enrolled in the study. At baseline, 66 (97.1%) patients were pasireotide naïve, while 2 (2.9%) were treated with pasireotide previously with 4 weeks of washout period prior to screening (Table 1). Of 68 patients received treatment during the core phase, 26 (38.2%) received pasireotide monotherapy and 42 (61.8%) received combination therapy. Fifty-two (76.5%) patients completed the 35-week core phase while 16 (23.5%) discontinued (Figure 1). All 68 patients were included in the full analysis set based on the intention to treat (ITT) principle. One of the protocol deviations observed during the study, was inclusion of 3 patients with normal mUFC value at screening visit (baseline) and assigning a treatment. The deviation category for the 3 patients was ‘failed inclusion criteria’ with screening mUFC value ≤ULN (137.95 nmol/24h) or mUFC calculated using ❤ UFC values or 2 out of 3 UFC values ≤ULN. One of these patients (baseline mUFC 37.37 nmol/24h ≤ULN) was discontinued from the study at Week 2 and due to lack of post-baseline mUFC assessment, was classified ‘non-responder’ at Week 35 assessment. The 2nd patient’s baseline mUFC value of 135.20 nmol/24h was close to ULN (137.95 nmol/24h) and was rescreened. Based on the rescreened mUFC value 306.5 nmol/24h, this patient was included in study, and the mUFC at Week 35 was 192.30 nmol/24h (non-responder at Week 35 assessment). For all study assessments, the scheduled screening visit’s first mUFC value (≤ULN) was used as baseline value. The 3rd patient (baseline mUFC value 131.77 nmol/24h) was discontinued from the study at Week 26 and was also observed for non-compliant schedule visit and medication dosages. The mUFC value recorded at Week 26 (88.95 nmol/24h) was ≤ULN and this last observation was carried forward to Week 35. Hence, the patient was classified ‘responder’, leaving one patient included in the study as responder as a protocol deviation.

Table 1
www.frontiersin.orgTable 1 Patient demographics and baseline characteristics.

Figure 1
www.frontiersin.orgFigure 1 Patient disposition. *If the study drugs were locally available at the end of the core phase, patients could switch over to the commercial supply and exit the extension phase. Only in countries where the drug was not locally available were patients given the option to enter the extension phase. Percentage for patients not entering the extension phase was calculated from the total number of patients enrolled in the study.

Twenty-nine (42.6%) patients continued treatment in the extension phase; 10 (34.5%) received pasireotide monotherapy and 19 (65.5%) received combination therapy. Twelve (41.4%) patients completed the extension phase, while 17 (58.6%) discontinued treatment before study end, most commonly for unsatisfactory therapeutic effect (n=8). The most common reason for discontinuation was adverse events (AEs): 5 (17.2%) patients with pasireotide monotherapy and 2 (5.1%) patients with combination therapy.

3.2 Efficacy: biochemical response

Overall, 34/68 (50.0%; 95% CI 37.6–62.4) patients achieved the primary endpoint, of whom 17 (50.0%) were receiving pasireotide monotherapy and 17 (50.0%) were receiving combination therapy. Patients with mild hypercortisolism (mUFC 1.0–<2.0 x ULN) at baseline were more likely to respond to both pasireotide monotherapy and combination therapy (n=15; 22.1%, Figure 2). Seven of 17 patients in the pasireotide monotherapy group met the primary endpoint based on their last available assessment prior to week 35. Even if the 3 patients who had mUFC ≤ULN at baseline were excluded from the primary analysis, 33/65 (50.7%; 95% CI 38.1–63.4) patients would have achieved the primary endpoint. The results are similar to the original analysis (34/68 (50.0%; 95% CI 37.6–62.4) based on the full analysis set.

Figure 2
www.frontiersin.orgFigure 2 Patients achieving mUFC ≤ULN at week 35. At baseline there were 23 patients with mild, 30 with moderate and 12 with severe hypercortisolism. mUFC, mean urine free cortisol; ULN, upper limit of normal.

For the overall study population (n=68), mUFC rapidly decreased from 501.6 nmol/24h (3.6 x ULN; SD: 488.66 nmol/24h) to 242.1 nmol/24h (1.8 x ULN; SD: 203.47 nmol/24h) at week 4 and mUFC remained below baseline levels up to week 35 (184.8 nmol/24h; 1.3 x ULN; SD:140.13 nmol/24h). For patients who received pasireotide monotherapy (n=26), mUFC( ± SD) decreased from baseline (442.1± 557.13 nmol/24h [n=26]; 3.2 x ULN) to week 35 (136.6 ± 127.77 nmol/24h [n=14]; 1 x ULN) and at the end of the study (111.2 ± 40.39 nmol/24h [n=5]; 0.8 x ULN) using the last-observation-carried-forward (LOCF). For those who did not normalize on pasireotide monotherapy (n=42), mUFC ( ± SD) decreased from baseline, i.e., last observation before starting cabergoline (280.20 ± 129.03 nmol/24h [n=40]; 2.0 x ULN) to week 35 (206.6 ± 141.96 nmol/24h [n=31]; 1.5 x ULN) and at the end of the study (219.60 ± 83.78 nmol/24h [n=7]; 1.6 x ULN) using the LOCF. During the core phase, mean serum cortisol decreased from 738.6 nmol/L (1.3 x ULN) at baseline to 538.2 nmol/L (0.95 x ULN) and ACTH levels from 16.3 pmol/L (2.7 x ULN) to 11.0 pmol/L (1.8 x ULN) at week 35.

During the extension phase, 25 patients had a mUFC assessment; of whom 12 (48%) had a mUFC ≤ULN at the end of the extension phase. During the extension phase, mUFC levels decreased slightly and fluctuated above and below the ULN up to the week 139 (Figure 3A), while mean serum cortisol remained below ULN (404 nmol/L; Figure 3B) and ACTH levels fluctuated from 8.2 pmol/L to 11.5 pmol/L) and remained above the ULN value (Figure 3C).

Figure 3
www.frontiersin.orgFigure 3 Mean actual change over time in (A) mUFC (B) serum cortisol, and (C) ACTH. ACTH, adrenocorticotropic hormone; mUFC, mean urine free cortisol; ULN, upper limit of normal .

Twenty-one of 38 (55%) patients achieved control with combination therapy at some point during the core or extension study, of whom 13 (62%) experienced escape (at least one UFC >ULN after previous control). The time to achieve control after starting cabergoline ranged from 14−;343 days. Notably, one patient received pasireotide 0.6 mg bid initially, dose increased to 0.9 mg bid at Week 17, followed by addition of cabergoline 0.5 mg od at Week 31. The patient achieved biochemical control (mUFC value of 120.15 nmol/24h) on the same day of the start of combination therapy. Clinically it is highly unlikely that biochemical control was achieved with single dose of cabergoline administration. Therefore, it could be considered that normalization was achieved while receiving pasireotide monotherapy. Also, the physician might have prescribed combination therapy before receiving the mUFC value of the (urinary) sample delivered on the morning of combination therapy initiation (while the patient was still on monotherapy). The patient continued combination therapy and maintained biochemical control up to Week 35 and beyond. Furthermore, at Week 59 the cabergoline dose was increased to 1.0 mg/day due to mUFC >ULN at previous visit (Week 51). The patient remained on pasireotide 0.9 mg bid/cabergoline 1.0 mg od combination therapy until the study end.

The median time to escape after achieving control with the addition of cabergoline was 58 days (range 28−;344). 10/13patients regained biochemical control with combination therapy. No patients on pasireotide alone experienced escape, probably due to the short observation time.

3.3 Clinical signs and symptoms of CD

Relative to baseline, pasireotide monotherapy was accompanied by reductions in median blood pressure, weight, BMI, waist circumference, and total cholesterol. Overall improvement in clinical measures persisted over time (Supplementary Table S1). Clinical improvements were also seen following the addition of cabergoline, particularly for hirsutism (Supplementary Figures S2S3).

Mean( ± SD) standardized CushingQoL score was 41.6(± 20.2) at baseline and increased to 47.6(± 20.8) at week 35 (Supplementary Table S2), indicating improvements in patients’ QoL (19).

3.4 Safety and tolerability

Median duration of exposure to pasireotide was 35.0 weeks (range 0−;268), with a median dose of 1.53 mg/day (range 0.29−;1.80). Median duration of exposure to cabergoline was 16.9 weeks (range 1−;215), with a median dose of 0.50 mg/day (range 0.44−;0.97).

All patients (N=68) reported at least one AE and 28/68 (41.2%) patients had a grade 3/4 AE (Table 2). The most common AEs (≥30%) were hyperglycemia and nausea (51.5% each), diarrhea (44.1%) and cholelithiasis (33.8%). Treatment-related AEs (TRAEs) were reported in 66/68 (97.1%) patients; the most frequent TRAEs (≥30%) were hyperglycemia and nausea (47.1% each), diarrhea (39.7%), and cholelithiasis (32.4%). Fourteen (20.6%) patients had ≥1 AE leading to discontinuation.

Table 2
www.frontiersin.orgTable 2 Summary of adverse events (≥10%), overall and by treatment regimen.

The most common AEs leading to discontinuation were increased gamma-glutamyl transferase (GGT) and hyperglycemia (two patients each, 2.9%). Twenty-three (33.8%) patients had ≥1 AE leading to dose adjustment or interruption. Details on special safety assessments such as hyperglycemia-related AEs, blood glucose, HbA1c, IGF-1 as well as hematological and biochemical abnormalities are presented in the Supplementary Appendix.

Three (4.4%) patients died during the study, two (2.9%) during the core phase and one (1.5%) during the extension. All deaths were considered unrelated to study medication. The causes during the core phase were multi-organ dysfunction syndrome for one patient aged 79 years and unknown for the other aged 34 years. Uncontrolled hypertension was reported as the cause of death for the patient aged 47 during the extension phase.

4 Discussion

The severe morbidity and increased mortality with uncontrolled CD highlight the importance of identifying an effective medical strategy. This study explored the potential of a synergistic benefit of the addition of cabergoline to pasireotide treatment in patients with CD.

Complete normalization of cortisol production is required to reverse the risks of morbidity and mortality in patients with CD (1). Two small studies showed clinical improvement of normalized UFC when cabergoline and ketoconazole were combined (2021). Benefit has also been reported with triple therapy with pasireotide, cabergoline and ketoconazole (18) and triple therapy with ketoconazole, metyrapone and mitotane in severe CD (22). In the current study, 50% of patients achieved the primary endpoint of mUFC ≤ULN at week 35 and a similar proportion (48%) sustained biochemical control throughout the extension phase. Notably, combination treatment doubled the number of patients who attained mUFC ≤ULN from the core phase to the end of the extension phase. In particular, mUFC was rapidly reduced with treatment, i.e., in most patients within 2 months, while measures of patient-reported outcomes also improved including QoL. Twenty-three patients (33.8%) who completed the core phase did not enter the extension phase. This was because only patients from countries where a commercial supply was unavailable were given the option to enter the extension phase.

This study confirms previous reports that patients with mild hypercortisolism at baseline were more likely to achieve mUFC control with pasireotide monotherapy than patients with moderate or severe hypercortisolism (623). In addition, patients with moderate hypercortisolism at baseline were more likely to achieve mUFC control with the addition of cabergoline. This supports that a combination therapy can be effective for patients with a wider range of disease severity. Accordingly, in vitro data may indeed indicate synergism between SSTR and D2 that might increase therapeutic efficacy (2425).

Improvements in clinical signs and symptoms with pasireotide monotherapy were consistent with published data (610). In the core phase, an improvement of blood pressure and BMI was observed with pasireotide monotherapy and, to a lesser extent, with combination therapy which may related to the difference in duration of biochemical remission.

The overall safety profile was consistent with that expected for pasireotide, with most AEs being mild/moderate (2627). There were no new safety signals identified with the addition of cabergoline. Common AEs including nausea, headache, dizziness, and fatigue are suggestive of steroid withdrawal symptoms associated with the decrease in UFC, although direct drug effects cannot fully be excluded. Adrenal insufficiency was not reported as side effect. Rates of hyperglycemia-related AEs (68%) were consistent with those in previous reports of pasireotide monotherapy (610). FPG increased with pasireotide monotherapy during the first 8 weeks of treatment and stabilized for the remainder of the study, including following the addition of cabergoline. These data highlight the vital role of blood glucose monitoring in these patients.

Both pasireotide and cabergoline are pituitary-targeted agents that act directly on the source of the disease via inhibition of ACTH release by the corticotroph tumor, which may be an advantage over steroid synthesis inhibitors. This study further confirms previous data reporting the benefits of pasireotide in combination with cabergoline in patients with CD (18). While not entirely elucidated, down-regulation of dopamine D2 receptors (D2R) expression, and post-receptor desensitization and/or tumor regrowth of corticotroph tumor cell were suggested as possible mechanisms for treatment escape (15). Moreover, different dopamine receptor patterns and/or D2R isoforms also influence the response and eventually the treatment escape. Treatment escape has been observed in some studies after long-term (7−;12 months) treatment with cabergoline (13), however it is possible that use of concomitant SRLs could potentially reduce the rate of escape. In this study, a total of 13 patients experienced treatment escape. However, 10 of these patients regained biochemical control. For 7 of these 10 patients, there was up titration of doses to a maximum of 1.8 mg/day of pasireotide and 1 mg/day of cabergolineAlthough pasireotide and cabergoline have shown long-term reduction in IGF-1 levels in patients with acromegaly (2829), there is little evidence for this effect in patients with CD (430). One study (n=17) found significant decreases in IGF-1 after 28 days’ treatment with pasireotide that was independent of UFC reduction. One-third of patients had low IGF-1 (30). Our study showed that almost half of patients (47.6%) had IGF-1 levels either above ULN or below LLN prior to the addition of cabergoline, and IGF-1 levels decreased relative to the baseline, with majority of values within the normal range during the core and extension phases up to week 99. Baseline levels of IGF-1 may already be low because of the suppressive effect of excess cortisol on the somatotropic axis (31).

Although clinicians have several therapeutic options at their disposal to treat hypercortisolemia associated with CD, the optimal treatment approach should be based on the individual clinical situation and the benefit–risk considerations for each patient. In this study, 13 patients had history of pituitary radiation, with a duration of at least 2.6 years (median 3.3 years) between the last radiation treatment and the observed response date. However, only 7/13 patients achieved the therapeutic target. Although there was a gap of > 2 years, we cannot exclude the role of radiation in normalizing UFC. Contrastingly, 6/13 patients treated with radiation did not achieve mUFC ≤ULN (responders) at Week 35. The impact of the adjuvant radiation therapy remains unclear.

The strengths of this study are that this is the largest and longest prospective study with pituitary-directed pharmacotherapy, to date, evaluating the addition of cabergoline to pasireotide in patients with CD, and this stepwise approach reflects real-world clinical practice (18). The study is limited by the open-label design and the fact that it was not a head-to-head comparative study of pasireotide only versus pasireotide plus cabergoline. This may be of importance in interpreting patient-reported outcomes. Several patients continued treatment for almost 2 years; however, interpretation of long-term data should be made with caution because of the small patient numbers. Notably, the last available assessment was carried forward for patients with missing mUFC value at week 35 including those who discontinued and were considered for response analysis. It should also be noted that the definition of loss of response, also known as escape, used in this study (at least one UFC value >ULN after previously achieving UFC ≤ULN) may overestimate the rate of apparent escape as UFC values may have fluctuated about the ULN range or been marginally elevated. The definition of treatment escape differs across studies, and we have used a very stringent one in this study, requiring only a single high UFC to meet the classification as escape. Thus, it is likely that some loss of biochemical control interpreted as escape is actually fluctuation of cortisol around the upper limit of normal range.

Other limitations include protocol deviations in including 3 patients with normal UFC at baseline (one patient was uncontrolled at rescreen, and one was discontinued at 2 weeks – both classified as

non-responders), lack of data on impact of radiation therapy without study drug in patients who gained biochemical control with adjuvant radiation therapy, lack of pituitary magnetic resonance imaging to detect pituitary tumor changes, lack of data about effective cabergoline dose and absence of cardiac valve assessment for mild to moderate severity in the medium term. Both pasireotide and cabergoline can induce tumor shrinkage in CD (693235) and it would be interesting to examine the combined effect on tumor size. This study used the subcutaneous formulation of pasireotide, whereas the most common usage currently is the long-acting formulation. Efficacy of long-acting pasireotide (36) seems higher compared to the subcutaneous formulation (7) and the effect of combination of long-acting pasireotide with cabergoline should be evaluated in future studies. No formal assessments were made for impulsive control disorders, which have been associated with dopamine agonists, including cabergoline (32333738). The reason that several different terms were used for hyperglycemia-related AEs is that they were reported as per discretion of each investigator. No additional psychiatric AEs were reported, although they were not exhaustively searched.

5 Conclusions

This is the first study demonstrating that pituitary-targeted combination treatment with pasireotide and cabergoline doubled the number of patients who attained mUFC ≤ULN. Both short- and long-term safety profile are consistent with known data for pasireotide and cabergoline. The low rate of discontinuation due to AEs suggests that pasireotide alone or as combination treatment is generally well-tolerated if appropriately monitored, even with prolonged treatment. The addition of cabergoline to pasireotide treatment in patients with persistently elevated mUFC could be an effective long-term strategy for enhancing the control of CD in a subset of patients, with close monitoring for possible escape.

Data availability statement

The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.

Ethics statement

The studies involving humans were approved by Hospital Britanico, Buenos Aires, Argentina; Ethische commissie University Hospitals Leuven, Leuven, Belgium; Universitair Ziekenhuis Gent, Gent, Belgium; Comite de Etica em Pesquisa Hospital Moinhos de Vento, Porto Alegre-RS, Brazil; Comitê de Ética em Pesquisa do Hospital de Clı́nicas, Universidade Federal do Paraná, Curitiba-PR, Brazil; Comissão de Ética para Análise de Projetos de Pesquisa, São Paulo – SP, Brazil; Ethics Committee for clinical trials, Sofia, Bulgaria; Comité Corporativo de Ética en Investigación, Bogotá DC, Colombia; Comite De Protection Des Personnes, Groupe Hospitalier Pellegrin – Bat, Bordeaux Cedex, France; Friedrich-Alexander Universitat Erlangen-Nurnberg, Medizinische Fakultat, Erlangen, Germany;National Ethics Committee, Cholargos, Athens, Greece; Ethics Committee for Clinical Pharmacology (ECCP), Budapest, Hungary; Institute Ethics Committee, New Delhi, India; Institutional Review Board (IRB) Ethics Committee Silver, Christian Medical College, Vellore, Tamil Nadu, India; Institute Ethics Committee, PGIMER, Chandigarh, India; Comitato Etico Dell’irccs Istituto Auxologico Italiano Di Milano, Milano, Italy; Comitato Etico Universita’ Federico Ii Di Napoli, Napoli, Italy; Jawatankuasa Etika & Penyelidikan Perubatan (Medical Research and Ethics Committee), d/a Institut Pengurusan Keshatan Jalan Rumah Sakit, Kuala Lumpur, Malaysia; Institutd Nacional De Neurologia Y Neurocirugia, Mexico City, Mexico; Clinica Bajio (CLINBA), Guanajuato, Mexico; Medische Ethische Toetsings Commissie, Rotterdam; Netherlands; CEIm Provincial de Málaga, Málaga, Spain; Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey; WIRB, Puyallup, WA, USA; Research Integrity Office, Oregon Health & Science University Portland, OR USA. The studies were conducted in accordance with local legislations and institutional requirements. The participants provided their written informed consent to participate in this study.

Author contributions

All authors directly participated in the planning, execution, or analysis, and have had full control of complete primary data, and hold responsibility for data integrity and accuracy. All authors contributed to the article and approved the submitted version.

Acknowledgments

We thank Julie Brown, Mudskipper Business Ltd, and Manojkumar Patel and Sashi Kiran Goteti, Novartis Healthcare Private Limited, for medical editorial assistance with this manuscript. We would also like to thank all investigators, sub-investigators, study nurses and coordinators, and patients who have made this study possible.

Conflict of interest

HP and RM were Novartis employees and owned Novartis stocks. AMP was employed by Novartis and Recordati. AC is a Novartis employee and owns Novartis stocks. RF received research grants from Strongbridge and Corcept, consulting fee from Recordati, honoraria and financial support for meetings and/or travel from HRA Pharma and Recordati, and attended advisory boards for Recordati. MF has received research support to Oregon Health & Science University as a principal investigator from Recordati and Xeris Strongbridge and has performed occasional scientific consultancy for Recordati, HRA Pharma, Sparrow, and Xeris Strongbridge. PK attended advisory boards for Recordati. MB’s institution received consulting fee and attended advisory boards from Recordati. DG-D received research grants from Recordati Rare Disease and Bayer, consulting fee from Abbott-Lafrancol, Biotoscana, PTC lab, Glaxo/Helou, Recordati Rare Disease, and Bayer, honoraria from Valentech Pharma, Sanofi, and Bayer, travel grants from Recordati Rare Disease, advocacy groups and other leadership roles from Asociación Colombiana de Endocrinologia and Asociación Colombiana de Osteoporosis y Metabolismo, and other financial and non-financial interests include Asociacion Colombiana de Endocrinologia y Metabolismo, Hospital Universitario Fundación Santa Fé de Bogota, and Asociación Colombiana de Osteoporosis y Metabolismo. CB received research grants from Novartis and Recordati, and consulting and speaker fee from Novartis. BB served as the principal investigator for grants to Massachusetts General Hospital from Cortendo/Strongbridge Xeris, Millendo, and Novartis and has occasionally consulted for Cortendo/Strongbridge Xeris, HRA Pharma, Novartis Recordati, and Sparrow. RP and his institution received research grants and honoraria from Pfizer, Ipsen, Novartis, Merck Serono, IBSA Farmaceutici, Corcept, Shire, HRA Pharma, ICON, Covance, Neuroendocrine CAH, Camurus, Recordati, Janssen Cilag, and CMED Clinical Services, received consulting fee from Recordati Rare Disease, Organon Italia, Siunergos Pharma, Corcept, S&R Farmaceutici S.p.A., DAMOR Farmaceutici, and Pfizer, attended advisory boards from Crinetics Pharmaceuticals, Recordati Rare Disease, Pfizer, and HRA Pharma.

The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The authors declare that this study received funding from Novartis Pharma AG. Novartis was involved in the study design, analysis, interpretation of data, and providing financial support for medical editorial assistance of this article.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fendo.2023.1165681/full#supplementary-material

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Keywords: somatostatin, pasireotide, cabergoline, Cushing’s disease, hypercortisolism

Citation: Feelders RA, Fleseriu M, Kadioglu P, Bex M, González-Devia D, Boguszewski CL, Yavuz DG, Patino H, Pedroncelli AM, Maamari R, Chattopadhyay A, Biller BMK and Pivonello R (2023) Long-term efficacy and safety of subcutaneous pasireotide alone or in combination with cabergoline in Cushing’s disease. Front. Endocrinol. 14:1165681. doi: 10.3389/fendo.2023.1165681

Received: 14 February 2023; Accepted: 11 August 2023;
Published: 09 October 2023.

Edited by:

Renato Cozzi, Endocrinology Unit Ospedale Niguarda, Italy

Reviewed by:

Przemyslaw Witek, Warsaw Medical University, Poland
Athanasios Fountas, General Hospital of Athens G. Genimatas, Greece

Copyright © 2023 Feelders, Fleseriu, Kadioglu, Bex, González-Devia, Boguszewski, Yavuz, Patino, Pedroncelli, Maamari, Chattopadhyay, Biller and Pivonello. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Richard A. Feelders, r.feelders@erasmusmc.nl

Present addresses: Alberto M. Pedroncelli, Chief Medical Office, Camurus AB, Lund, SwedenRicardo Maamari, Global Medical Affairs, Mayne Pharma, Raleigh, NC, United States

These authors have contributed equally to this work

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

From https://www.frontiersin.org/articles/10.3389/fendo.2023.1165681/full

Multiple Clinical Indications of Mifepristone: A Systematic Review

​Abstract

Mifepristone and misoprostol are globally used medications that have become disparaged through the stigmatization of reproductive healthcare. Patients are hindered from receiving prompt treatment in clinical scenarios where misoprostol and mifepristone are the drugs of choice. It is no exaggeration to emphasize that in cases where reproductive healthcare is concerned. The aim of this paper is to discuss the different indications of mifepristone and to delineate where the discrepancy in accessibility arises. For this systematic review, we included publications citing clinical trials involving the use and efficacy of mifepristone published in English within the date range of 2000 to 2023. Five databases were searched to identify relevant sources. These databases are Google Scholar, MEDLINE with full text through EBSCO, and three National Center for Biotechnology Information (NCBI) databases (NCBI Bookshelf, PubMed, and PubMed Central). Twenty-three records were ultimately included in this review. Mifepristone has been shown to have therapeutic effects in the treatment of psychiatric disorders, such as major depressive disorder and psychotic depression. There was a significant decrease in depression and psychiatric rating symptoms for patients taking mifepristone versus placebo with no adverse events. Mifepristone has also been shown to improve treatment course in patients with Cushing’s disease (CD) who failed or are unable to undergo surgical treatment. In addition, mifepristone has been shown to be a successful treatment option for adenomyosis and leiomyomas. Patients had a statistically significant decrease in uterine volumes following mifepristone treatment, which aided in the alleviation of other symptoms, such as blood loss and pelvic discomfort. Mifepristone is a synthetic steroid that has immense potential to provide symptomatic relief in patients suffering from a wide array of complicated diseases. Historically, mifepristone has been proven to have an incredible safety profile. While further research is certainly needed, the politicization of its medical use for only one of its many indications has unfortunately led to the willful ignorance of its potential despite its evidence-based safety profile and efficacy.

Introduction & Background

Mifepristone is a synthetic steroid derived from norethindrone and therefore has antagonistic activity against progesterone and glucocorticoid receptors. Misoprostol is a synthetic prostaglandin E1 analog that works through the direct stimulation of prostaglandin E1 receptors. Recently, these medications have become disparaged due to their associations with the controversial medical procedure known as abortion. Abortions, however, have been so common that one out of four women will have had an abortion by the time they reach the age of 45 [1]. It is estimated that 3.7 million women have used mifepristone and misoprostol for medication abortions since they were first approved by the Food and Drug Administration (FDA) in 2000 [1]. Mifepristone followed by misoprostol is up to 14 times safer than carrying the patient’s pregnancy to term [1]. Aside from abortion, mifepristone is used for both gynecologic and obstetric conditions. Obstetric conditions include induction of labor, postpartum hemorrhage, intrauterine fetal demise, ectopic pregnancies, and miscarriages [2]. Gynecological conditions that can be treated with mifepristone include abnormal uterine bleeding, post-coital contraception, and treatment of gynecological cancers [3]. Due to the stigmatized nature of abortion, however, patients are hindered from receiving prompt treatment in clinical scenarios where mifepristone is the drug of choice. It is no exaggeration to emphasize that in cases where reproductive healthcare is concerned, every second counts [3]. Legislation that varies across states further impacts patients who risk their lives and health as they attempt to navigate their care plan across borders. Travel costs, time-off, childcare, transportation, and living accommodations are just a few more of the factors patients must take into consideration when they are forced to seek life-saving care outside of their homes [3].

Mifepristone is a medication that has multiple therapeutic applications, such as treating leiomyomas, psychotic depression, and post-traumatic stress disorder (PTSD). However, its use is restricted in many countries because of its abortifacient effect. This is a logical fallacy that deprives patients of a beneficial and safe treatment option. This systematic review aims to explore the evidence-based uses of mifepristone and how it can improve patients’ health outcomes. The clinical indications that will be discussed are adenomyosis, leiomyomas, psychotic depression, PTSD, and Cushing’s disease (CD).

Review

Methods

Eligibility Criteria

For this systematic review, we included publications of clinical trials and systematic reviews citing clinical trials relating to the clinical use of mifepristone and published in English within the date range of 2000 to 2023.

Info Sources

Five databases were searched to identify relevant sources. These databases include Google Scholar, MEDLINE with full text through EBSCO, and three National Center for Biotechnology Information (NCBI) databases (NCBI Bookshelf, PubMed, and PubMed Central).

Search Strategy

For each database, we inputted “clinical use of mifepristone” as our search term. The populated results were then narrowed down to those published in the English language and within the date range of 2000 to 2023 using automated search tools.

Selection Process

The titles and abstracts of the remaining records were then screened, and those deemed relevant to clinical uses of mifepristone and its efficacy were included for comprehensive review. This initial record search in three of the four databases (Google Scholar, MEDLINE, and PubMed) was completed by three separate reviewers. The initial record search in the remaining two databases (NCBI Bookshelf and PubMed Central) was completed by another individual reviewer.

Data Collection Process

After the initial record search, 60 records were deemed relevant to the study topic and compiled for a more comprehensive review. Two records were found to be duplicates and removed. Each of the four reviewers read the remaining 58 records and voted on the eligibility of the publication for inclusion in our review. Older publications that were expanded upon in more recent study trials were excluded to reduce redundancy. In addition, for records with similar study protocols, only the more recently published record was included. Ten records were excluded from the review due to ineligible study design. For those records that were not unanimously accepted (at least one reviewer voted for exclusion), the record was excluded. To ensure that the data utilized in this review were backed by sufficient evidence, the reviewers organized the remaining records into groups based on the disease mifepristone was being studied to treat. After further discussion, it was decided to exclude the records in the groups that lacked at least three separate clinical trials on the use of mifepristone in the treatment of the disease. Thirty articles were excluded. Seven of the 18 remaining records were systematic reviews, and citation searching of the records found four additional records that met the eligibility criteria. The remaining 23 records were included for further review.

Data Items

Of the remaining 23 records deemed acceptable for inclusion, only studies with statistically significant findings regarding the clinical use of mifepristone were included for detailed analysis. One record was excluded due to early termination of the trial. Our records include two open-label studies, four retrospective studies, seven reviews (systematic, meta-analysis), one wet lab (human specimen was used), five long-term safety extension articles, and seven randomized control experimental trials.

Study Risk-of-Bias Assessment

We assessed the risk of bias (RoB) in the studies included in the review using the revised Cochrane RoB tool for randomized trials (RoB 2). The five domains assessed were (1) RoB arising from the randomization process, (2) RoB due to deviations from the intended interventions (effect of assignment to intervention and effect of adhering to intervention), (3) missing outcome data, (4) RoB in the measurement of the outcome, and (5) RoB in the selection of the reported result. Each randomized control trial included in this review was assessed for RoB by two authors working independently using the RoB 2. For those studies in which the assessing authors came to different conclusions, the remaining two authors completed independent RoB 2 assessments of the study in question, and the majority of findings was accepted. Utilizing the methodology for assigning the overall RoB for each study as outlined by the RoB 2 tool, each study was designated as having “low risk of bias” or “high risk of bias.” After an initial assessment, both authors deemed the nine randomized control studies had a low RoB.

Effect Measures

Analysis of the studies included a focus on statistically significant findings that varied between control and intervention groups as defined by a p-value less than 0.5. As each study had its own parameters and primary and secondary endpoints, we focused our analysis on the safety and clinical efficacy of mifepristone as measured and reported by the authors of the studies included.

Synthesis Methods

As previously mentioned, as the studies included in this review vary widely in their study population and intervention design, our analysis focused on qualitative synthesis of study outcomes. These outcomes were categorized as the clinical efficacy and safety of mifepristone for CD, psychiatric disorders, and select gynecological diseases (adenomyosis and leiomyomas).

Certainty Assessment

To assess the certainty of the body of evidence regarding the studies included in our review, two reviewers applied the five Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) considerations (study limitations, inconsistency of results, indirectness of evidence, imprecision, and publication bias) to each study. Accordingly, the included studies were categorized as having high, moderate, low, or very low certainty of evidence based on the GRADE criteria. After the assessment, both reviewers deemed that all records had high certainty of evidence.

PRISMA-2020-flow-diagram-for-new-systematic-reviews-that-included-searches-of-databases,-registers,-and-other-sources
Figure 1: PRISMA 2020 flow diagram for new systematic reviews that included searches of databases, registers, and other sources

*Consider, if feasible to do so, reporting the number of records identified from each database or register searched (rather than the total number across all databases/registers). **If automation tools were used, indicate how many records were excluded by a human and how many were excluded by automation tools.

PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses

Results

Psychiatric Implications

Based on the analyses, numerous trials demonstrated the profound therapeutic effect that mifepristone can have on psychiatric disorders. In a double-blind study following 19 patients with bipolar disorder, researchers studied neurocognitive function and mood in patients treated with mifepristone vs. the placebo [4]. Significant improvements in verbal fluency and spatial working memory were seen in the group treated with mifepristone. The Hamilton Depression Rating Scale (HDRS) and Montgomery-Asberg Depression Rating Scale (MADRS) scores also improved from baseline (i.e., lower scores) measurements in these patients. It is worth noting that these improvements were seen in as little as two weeks, which is quicker than what is normally seen with typical therapeutic agents for bipolar disorder (lithium/valproic acid) [4].

The most extensive research demonstrated the benefits of using mifepristone with major or psychotic depression [5]. It is important to note that approximately 20% of patients living with major depression experience psychotic symptoms [6]. A randomized, double-blind study looked at 30 participants with psychotic major depression (PMD) and treated them with mifepristone 600 mg or a placebo for eight days. Using the HDRS and Brief Psychiatric Rating Scale (BPRS) to quantify baseline levels of symptoms, results from eight days later showed that mifepristone was significantly more effective in reducing psychotic symptoms compared to the placebo group [6]. By day 8, nearly half of the participants attained a 50% reduction in the BPRS compared to the placebo group (p<0.046) in addition to lower HDRS scores (although this was not found to be significant). Moreover, when researchers looked further into the use of mifepristone in psychotic depression disorders, they discovered a correlation between higher plasma levels of mifepristone and a reduction in psychotic symptoms [7]. More specifically, the strongest reduction in psychosis symptoms was found to be associated with doses of 1200 mg/day of mifepristone, which resulted in a statistically significant reduction in psychotic symptoms (p<0.0004) [7]. The drug was also well tolerated and demonstrated a large safety margin in contrast to the numerous common adverse effects that patients experience when placed on standard treatment options (i.e., antipsychotics). In another double-blind, placebo-controlled study that took place over four days, five participants diagnosed with psychotic major depression were administered 600 mg of mifepristone [5]. The HDRS and BPRS scores were used, and the results showed that all five participants’ depression ratings decreased – a nearly statistically significant finding (p<.07) [5]. Likewise, four out of the five BPRS scores declined, approximating to a 32.5% decline, which is comparable to the 40% decline seen with traditional antipsychotic treatments that span six to eight weeks. Once again, no adverse effects were reported.

The use of mifepristone has been explored in many cognitive disorders, including Alzheimer’s disease. One study found that patients with mild to moderate Alzheimer’s disease displayed improvement on the Alzheimer’s disease assessment cognitive subtest – by 2.67 as opposed to the 1.67 decline in patients treated with a placebo [5]. Although not statistically significant, this finding encourages further studies to continue exploring the psychiatric and neurologic use of mifepristone.

Cushing’s Disease

Multiple trials have been conducted regarding the use and efficacy of mifepristone in the treatment of CD. Although surgical intervention to remove the source of excess cortisol production is the current mainstay of treatment, clinical trials have focused on the treatment with mifepristone for medical therapy, especially in patients who have failed surgical intervention or for those who are not good candidates for surgery.

Accordingly, a retrospective study of 20 patients with hypercortisolism (12 with adrenocortical carcinoma, three with ectopic adrenocorticotropic hormone (ACTH) secretion, four with CD, and one with bilateral adrenal hyperplasia) found clinically significant improvement in excess cortisol-induced symptoms in 15 out of 20 patients [4]. Patient responses to mifepristone treatment were monitored by clinical signs of hypercortisolism (signs of hypercortisolism, blood pressure measurements, and signs of adrenal insufficiency) and serum potassium and glucose. The study found that 15 out of 20 patients showed significant clinical improvement in excess cortisol-induced symptoms. Psychiatric symptoms and blood glucose levels also improved in the patients [4]. Of note, 11 out of 20 trial participants exhibited moderate to severe hypokalemia as a side effect, although only one patient had to leave the study early due to severe adverse effects [4].

In another well-known study, 50 patients were assessed at baseline and during intervention (total of six times) for 24 weeks, referred to as the SEISMIC study [8]. Changes in oral glucose tolerance tests over time were used to assess the mifepristone effect in type 2 diabetes millets (T2DM)/impaired glucose tolerance patients. Changes in diastolic blood pressure (BP) over time were used to measure the effect of mifepristone in hypertensive cardiogenic shock (CS) patients [8]. Results found a statistically significant improvement in symptoms in both groups: diabetic patients had improvement in response to oral glucose test, decreased A1C, and decreased fasting glucose, and hypertensive patients had decreased diastolic BP or reduction in antihypertensive medications [8]. In addition, the waist circumference and hemoglobin A1C (HbA1C) also improved, and study findings concluded that mifepristone use has an acceptable risk-benefit ratio for six months of treatment [8].

Several extension studies were later performed utilizing the data found during the SEISMIC study [9]. One such study assessing weight loss in patients who participated in the SEISMIC study also found statistically significant improvement in patients with CD. After one-week mifepristone period (patients who chose to participate in this follow-up study had to be assessed to ensure it was safe for them to enroll in this study), 30 patients were enrolled and started on once daily mifepristone at the dose they were taking when the SEISMIC study concluded [9]. The patient’s weight was assessed at baseline and week 24 of the SEISMIC study, and for this study, the follow-up weight was taken at months 6, 12, 18, and 24 and a final visit. Data were assessed for 29 of the participants and statistically significant decreases in weight were found for all participants from baseline to end of the SEISMIC study, and the maintenance of weight loss was statistically significant in all participants at their final visit to this study as well [9].

Another SEISMIC extension study focused on monitoring the effects of mifepristone treatment in CD on ACTH levels and pituitary MRI findings [10]. Serum ACTH, urinary, and salivary cortisol levels were monitored during the SEISMIC study (baseline, day 14, and weeks 6, 10, 16, and 24) and once after a six-week mifepristone-free “washout” period. ACTH levels were then monitored one month later and then routinely every three months during the intervention period, which varied per participant [10]. Serum cortisol measures were assessed during the SEISMIC study at the intervals mentioned previously and then every six months during the extension study. Pituitary MRI studies were taken prior to mifepristone administration during the SEISMIC study and at weeks 10 and 24 [10]. Repeat imaging was then taken every six months during the extension study. On average, ACTH levels increased greater than twofold (2.76 ± 1.65-fold over baseline; p<0.0001 vs. baseline) in patients during the SEISMIC and extension study periods and decreased to near baseline levels after six weeks of mifepristone discontinuation [10]. Serum cortisol levels in both the initial intervention and extension period increased as well, although a higher mean cortisol level was seen during the extension study intervention (SEISMIC: 1.97 ± 1.02-fold increase; p<0.0001 vs. baseline; extension study: 2.85 ± 1.05-fold increase; p<0.0001 vs. baseline) [10]. In comparing the baseline and post-intervention MRI images, 30 out of 36 patients showed no progression in pituitary tumor size with mifepristone intervention, two patients showed regression of tumor size, and three patients showed evidence of tumor progression. One patient was found to have a tumor post-intervention despite a negative initial MRI at baseline [10].

A retrospective analysis of data collected during the SEISMIC study utilized oral glucose tolerance test data to assess the mifepristone treatment effect on the total body insulin sensitivity, beta cell function, weight, waist circumference, and additional parameters [11]. The analysis found improved total body insulin sensitivity in all participants, with the greatest improvement occurring from baseline to week 6. The weight and waist circumference both decreased by week 24 [11].

An additional important six-month study was done on 46 patients with refractory CS and either DM2, impaired glucose tolerance, or diagnosis of HTN in which mifepristone treatment was administered daily [12]. Patients were examined by three separate reviewers using global clinical response assessments (-1 = worsening, 0 = no change, 1 = improving) measured by eight clinical categories: glucose control, lipids, blood pressure, body composition, clinical appearance, strength, psychiatric/cognitive symptoms, and quality of life at weeks 6, 10, 16, and 24. A positive correlation with increasing GCR scores was found by week 24, with 88% of participants showing statistically significant improvement (p<0.001) [12].

Adenomyosis/Leiomyoma

Adenomyosis and leiomyomas are common gynecological conditions that affect large portions of the female population. Multiple trials have proven mifepristone’s success in treating endometriosis and various forms of cancer. Current data shows that mifepristone is well tolerated and has mild side effects in certain long-term clinical settings.

In one trial following mifepristone and its effects on adenomyosis, 20 patients were treated with 5 mg oral mifepristone/day for three months [13]. After the three-month trial, patients demonstrated a statistically significant (p<0.001) reduction in uterine volume as was measured through transvaginal ultrasound. These patients were also found to have significantly decreased CA-125 markers (a marker of adenomyosis and an increase in uterine size) and significantly increased hemoglobin concentration The patient’s endometrial tissue was then obtained from each patient during their hysterectomy [13]. The endometrial tissue samples were treated with varying concentrations of mifepristone for 48 hours. They found that mifepristone significantly decreased the viability of endometrial epithelial and stromal cells in adenomyosis and can induce their apoptosis as well [13]. This concentration-dependent inhibitory effect was most significantly seen with concentrations of mifepristone above 50 μmol/L at 48 hours. The same study showed that mifepristone demonstrated another dose-dependent relationship in the inhibition of the migration of ectopic endometrial and stromal cells. This finding is significant as the migratory nature of the patient’s endometrial and stromal cells is the pathogenesis behind adenomyosis [13].

Another study looked at the effect of mifepristone in combination with high-intensity focused ultrasound (HIFU) and levonorgestrel-releasing intrauterine system (LNG-IUS) in the treatment of adenomyosis [13]. Out of 123 patients, 34 patients were treated with HIFU alone, 29 patients were treated with HIFU combined with mifepristone, 10 patients with HIFU combined with LNG-IUS, and 50 patients with HIFU combined with mifepristone and LNG-IUS [13]. In the group treated with HIFU combined with mifepristone and LNG-IUS, the uterine volume was significantly reduced after treatment at 3, 6, 12, and 24 months compared to the previous treatment (p<0.05). Dysmenorrhea was measured using a visual analog score (VAS). In the combination group of mifepristone, HIFU, and LNG-IUS, VAS scores decreased from 80.82 ± 12.49 to 29.58 ± 9.29 at 24 months [13]. This was significantly lower than the three other treatment groups (p<0.05). The combination group of mifepristone, HIFU, and LNG-IUS also demonstrated statistically significant decreases in the menstrual volume and CA-125 serum markers [13]. Hemoglobin levels were not statistically different among the four treatment groups, but it is postulated that this could have been due to the fact that the patients who were anemic had been treated with different medications to improve their Hb aside from the trial medications [13].

Uterine leiomyomas are another gynecological condition that has been found to improve with the use of mifepristone as well. Insulin-like growth factor 1 (IGF-1) has been found to be overexpressed in leiomyomas [14]. This study showed that mifepristone inhibited the gene expression of IGF-1, and the reduction in symptoms correlated with a decrease in IGF-1 expression although the mechanism is not fully understood [14]. A meta-analysis studied the effects of mifepristone on uterine and leiomyoma volumes of 780 women from 11 randomized controlled trials. Mifepristone at doses from 2.5, 5, and 10 mg was found to effectively reduce uterine and leiomyoma volumes and alleviate leiomyoma symptoms at six months [6]. Pelvic pain, pelvic pressure, and dysmenorrhea were found to be alleviated after three months of treatment. Mifepristone also decreased the mean loss of blood during menstruation and a statistically significant increase in hemoglobin. No significant difference was found among varying dosages of 2.5, 5, and 10 mg other than increased frequency of hot flashes in patients of the 10 mg group. Another review investigated six clinical trials involving 166 women and the effects of 5-50 mg mifepristone for three to six months on leiomyomas [3]. The review demonstrated that daily treatment with all doses of mifepristone resulted in reductions in pelvic pain, pelvic pressure, dysmenorrhea, and uterine and leiomyoma volume size by 26-74%. Even doses of 2.5 mg of mifepristone resulted in significant improvement in the quality of life scores although there was little reduction in leiomyoma size at this dose [3]. This review also reported the rapid correction of uterine bleeding, amenorrhea, and increases in hemoglobin levels following treatment with 50 mg of mifepristone on alternating days. Even vaginal mifepristone has demonstrated efficacious results in the improvement of leiomyomas. In one such trial, the effects of daily 10 mg vaginal mifepristone were studied in 33 women from the ages of 30-53 [15]. Vaginal mifepristone significantly reduced leiomyoma volume and reduced the effects of symptoms on the patient’s quality of life as measured by the Uterine-Fibroid Symptoms Quality of Life questionnaire (UFS-QoL). It is important to note that the only significant side effect found in this review of trials was hot flashes at doses of mifepristone at 10 mg or more. Mifepristone was otherwise generally well tolerated with minimal if any adverse effects [15].

Discussion

Adenomyosis is a gynecologic condition that is characterized by the growth of endometrial cells into the myometrium, resulting in a globally enlarged uterus and an associated increase in CA-125 [16]. This marker is classically known to be an ovarian tumor marker; however, in this class, it reflects the increase in uterine glandular size. Although it is often labeled as a “benign” disease, it affects around 20% of reproductive-aged women. This condition can lead to dysmenorrhea, infertility, and menorrhagia in addition to detrimental effects on a patient’s mental health [16]. Despite 20% of affected patients being under the age of 40, the gold standard of treatment is a hysterectomy. Hysterectomies may often not be wanted by patients as it is an invasive surgery that comes with several potential complications of its own. It is important to note that due to the large percentage of patients with adenomyosis who are of reproductive age, hysterectomies may not be an appropriate standard method of treatment. To rob patients of their fertility without attempting medication therapy with mifepristone first is an act of injustice. Surgery alone comes with many complications and the possibility of recurrence. The ability of physicians to manage their patient’s pain and symptoms should be guided medically before surgical sterilization is considered. Many of these patients are forced to seek alternative non-invasive treatments instead of medication therapies to preserve their fertility.

HIFU and LNG-IUS are noninvasive therapies for adenomyosis that can be used in patients who refuse hysterectomies or for those who are not good candidates [16]. The pitfalls of these procedures include the fact that 20% of patients on HIFU alone end up relapsing, and LNG-IUS cannot be used in patients with a uterine size that is >12 weeks gestation or a uterine cavity depth that is >9 cm. Because adenomyosis is an estrogen-dependent disease, gonadotropin-releasing hormone agonists (GnRH-a) are also often used in combination with HIFU and LNG-US. Through the inhibition of the secretion of estrogen, GnRH-as facilitate reduced pelvic pain, reduced bleeding, and reduced uterine cavity size [16]. Reduction in cavity size is significant as this alone can lead to improved pain and reduced bleeding and allows patients to qualify for LNG-US where their previous uterine cavity size would have prevented their candidacy. Its current limitations include price (>$200/month), induction of premenopausal syndrome, and high rates of relapse following drug cessation [16]. Mifepristone offers a cheaper alternative (<$4/month) with significantly improved outcomes in reduced uterine cavity size, decreased dysmenorrhea pain scale score, and lower menstruation volume scores [16]. Mifepristone is also able to provide such results without the bone loss that is commonly associated with GnRH-analogs [3]. This is because mifepristone allows for serum estradiol to remain within the patient’s physiologic follicular phase range [3]. In addition, mifepristone is able to significantly reduce serum levels of CA-125 and improve hemoglobin levels in patients with menorrhagia. These reductions in CA-125 demonstrate marked reductions in the size of glands of the uterus of these patients. Through the reduction of cavity size, mifepristone can not only offer therapeutic relief but also allow patients to qualify for noninvasive LNG-US procedures, which can offer further therapeutic benefits. Patients should have the option to explore all potential medical therapies before opting for surgical correction.

Leiomyomas, or uterine fibroids, are another commonly encountered gynecologic condition and represent the most common benign tumors found in the female population. These benign smooth muscle tumors are estrogen-sensitive and can rarely develop into malignant leiomyosarcomas. Nearly 20-50% of patients with these fibroids experience symptoms, such as abnormal uterine bleeding (AUB), infertility, pelvic pain, and miscarriages [17]. Currently, the only treatment for this common condition is surgery. Two medications that are commonly used for preoperative reductions in leiomyoma size are mifepristone and enantone. Enantone is a gonadotropin-releasing hormone analog that has shown significant improvement in leiomyoma shrinkage, correction of anemia, and correction of AUB [17]. Through its MOA, however, enantone can lead to harmful adverse effects, such as menopausal symptoms and bone mineral loss. Using hormone supplementation to negate these side effects leads to reduced effectiveness of enantone in fibroid size reduction. Several studies have shown that progesterone plays a large role in the proliferation of leiomyoma growth [17]. Mifepristone, therefore, offers an effective alternate solution by producing the same results without enantone’s adverse effects. When comparing enantone to mifepristone, the two medications both resulted in statistically significant reductions in fibroid size, reduction in dysmenorrhea, reduction in non-menstrual abdominal pain, and increased Hgb/Hct/and RBC count despite differences in dosage [17]. However, mifepristone was able to maintain the patients’ premenopausal levels of estrogen, whereas patients on enantone were found to have estrogen levels of menopausal patients. Furthermore, patients who were treated with enantone also reported more adverse events compared to those in the mifepristone group [17]. Vaginal use of mifepristone has also been shown to significantly reduce leiomyoma size and improve symptoms of anemia while lowering systemic bioavailability of mifepristone [15]. Through its concentrated distribution to uterine tissue, vaginal mifepristone can lead to increased improvement in its clinical outcomes. Vaginal mifepristone showed statistically significant improvements in leiomyoma volume change, USF-QoL, and decreased bleeding intensity at the end of the three-month trial and three months after treatment [15]. For these reasons, mifepristone can be used effectively for conservative therapy in patients suffering from leiomyomas and should be considered a viable option for patients not wishing to undergo surgery.

CD refers to hypercortisolism that is caused by pituitary adenomas, adrenal neoplasias, or paraneoplastic ACTH secretion. Hypercortisolism in these patients leads to the development of skin changes, HTN, obesity, insulin resistance, dyslipidemia, anovulation, skeletal disorders, and neuropsychiatric disorders [18]. Patients suffering from these conditions endure a severely decreased quality of life and increased morbidity and mortality. The syndromic nature of this disease prompts delayed diagnosis and further increases the mortality and morbidity of this population [18]. CS therefore necessitates effective and rapid treatment options to diminish harm and clinical burden. The current first-line treatment for CD is pituitary surgery despite its nearly ⅓ relapse rate within 10 years postoperatively [18]. In these patients and patients with recurrent CD, further treatment options are necessitated. These options include adrenal surgery, pituitary radiotherapy, or medication therapy. Radiotherapy further delays symptomatic relief as it usually takes years before excess cortisol levels are managed. It also carries the risk of the patient developing hypopituitarism due to subsequent pituitary damage [18]. While surgery of the adrenal glands can quickly achieve control of excess cortisol, it also carries a risk of permanent adrenal insufficiency. Medication therapy can be used preoperatively, postoperatively, and as adjunctive therapy to radiotherapy. These drug classes include somatostatin analogs, dopamine agonists, and adrenal steroidogenesis inhibitors [18]. The most commonly used medication is the adrenal steroidogenesis inhibitor ketoconazole. While it has been proven to be effective and rapid in its success, doses may need to be frequently increased due to the cortisol blockade that occurs in CD patients [8]. In fact, due to the hormonal imbalances in CD patients, many medications often have to be dose adjusted to achieve therapeutic effect. It is also important to note that many of the medications that are used are not easily tolerated when doses are increased or adjusted frequently. The use of mifepristone has demonstrated statistically significant results in weight reduction, insulin resistance, depression, HTN, and quality of life in CD patients [10]. Furthermore, mifepristone can also be used effectively in patients experiencing cortisol-induced psychosis during acute exacerbations of hypercortisolism. While not included in the classes of more commonly used drugs for CD, mifepristone has been approved by the FDA for the treatment of CD when associated with disorders of glucose metabolism. This is undoubtedly due to the stigmatization of mifepristone and the subsequent reluctance of clinicians to incorporate it into their treatment plans.

Neuropsychiatric disorders have been investigated for their associations with dysregulations of the hypothalamic-pituitary-adrenal axis (HPA) and increases in cortisol levels. Studies have shown that patients suffering from depression, schizophrenia, and psychotic depression have elevated levels of cortisol and increased activity of their HPA [19]. The role of cortisol in psychiatric disorders is evidenced by the adverse psychiatric effects that patients can develop in response to exogenous glucocorticoid use through subsequent increases in cortisol. These include delirium, depression, mania, or psychosis. When functioning normally, HPA activity and cortisol secretion are maintained through sensitive negative feedback systems involving glucocorticoid receptors (GCRs) and mineralocorticoid receptors (MCR) [19]. At low doses, cortisol preferentially binds to MCR. As cortisol levels rise, it begins to bind to GCR and thereby initiates the negative feedback loop. Antipsychotics that are typically used work by reducing cortisol levels. Mifepristone, when dosed at >200 mg/day, selectively binds only to GCR and has no effect on MCR [19]. Through its sole inhibition of GCR, it ensures that normal cortisol homeostasis is maintained while ensuring that excess high levels of cortisol are blocked. This was evidenced by the statistically significant correlation between rising plasma concentrations of mifepristone and improvement of psychotic symptoms [20].

The hippocampus is a region of the temporal lobe that is most notably recognized for its role in learning and memory. Further studies have shown correlations between hippocampal atrophy and patients with severe depression, PTSD, and schizophrenia. It is postulated that this hippocampal atrophy leads to persistently high levels of cortisol, worsening these patient’s psychiatric symptoms. Administration of mifepristone to patients with combat-related PTSD demonstrated significant benefits in quality of life and psychiatric improvement. Psychotic major depression is another psychiatric condition that affects around 20% of patients with major depression [7]. When mifepristone was used to treat psychotic depression, patients were able to achieve rapid antipsychotic effects that lasted for weeks after the medication therapy ended. It should be noted that patients suffering from PMD generally have increased cortisol levels even with standard antidepressant therapy alone [7]. Some patients are even unresponsive to electroconvulsive therapy. The ability of patients suffering from psychotic depression to achieve rapid relief is imperative as these patients are more susceptible to suicidal ideation, especially during an episode of psychosis [7]. Bipolar disorder is another mood disorder that has been found to be associated with high levels of cortisol, dysfunction of the HPA axis, and GR dysfunction. Several neuroendocrine studies demonstrated that around 43% of bipolar patients with depression were also dexamethasone-suppression-test (DST) nonsuppressors [7]. Further studies found that bipolar patients suffering through relapse and recovery had abnormal dexamethasone/corticotropin-releasing hormone (dex/CRH) test results [21]. These abnormal (dex/CRH) findings were also seen in healthy patients who had certain genetic predispositions for mood disorders [21]. Regarding these HPA dysfunctions, GR has been implicated in being an important modulator of neurocognitive function and mood. This can be evidenced through research findings that report increased GR number and GR binding in brain tissue following the administration of antidepressants in depressed patients [21].

Mifepristone’s unique advantage is that its selective role as a GR antagonist was also found to increase both MR and GR binding in the frontal cortex. In fact, data from Young et al. [21] reveals significant improvement in frontal cortex functioning following clinical mifepristone trials. These results were seen through improvements in spatial working memory function and reductions in the HDRS17 and MADRS. They also demonstrated significant improvement in verbal fluency from baseline. These improvements in neurocognitive functioning were measured when the subjects’ mood was similar to their baseline or did not vary when compared to the placebo group [21]. This key finding suggests that improvements in neurocognitive functioning were not solely related to improvements in mood or depression. Mifepristone achieves these improvements in neurocognitive function through its selective activity towards GR within the frontal cortex. Furthermore, patients are also able to achieve symptomatic improvement two weeks after the initiation of treatment [21]. The rapid nature of mifepristone adds further clinical benefit as classic bipolar treatments take longer to achieve therapy and the fact that treatment plans for patients with bipolar disorder are tricky to individualize. Other commonly known psychiatric disorders are treated with antipsychotics. While these medications often come with a large array of adverse effects, weight gain, metabolic derangements, and glucose intolerance have been a few of the more frequently reported negative effects. While the exact cause of the weight gain is unknown, mifepristone was shown to significantly reduce weight gain in patients when taken alongside risperidone or olanzapine [21]. As discussed previously, mifepristone also has the ability to significantly improve insulin resistance, thereby further improving the AE patients may experience on antipsychotics. Therefore, through mifepristone’s selective activity as a GCR antagonist, it has immense potential as a psychiatric therapeutic agent.

Conclusions

Mifepristone is a synthetic steroid that has immense potential to provide symptomatic relief in patients suffering from a wide array of complicated diseases. Prednisone, dexamethasone, and anabolic steroids are also synthetic steroids that are commonly used. Despite being a part of the same class as mifepristone, none of these medications fall under as much legal, political, and social duress as mifepristone. This is in spite of the fact that mifepristone has been proven to have an incredible safety profile since its introduction to the public in the 1980s. In fact, its mortality rate is significantly lower than that of Tylenol, NSAIDs, penicillin, and phosphodiesterase inhibitors. While further research is certainly needed, its involvement in politics has unfortunately led to the willful ignorance of its medical potential despite its evidence-based safety profile and efficacy.

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From https://www.cureus.com/articles/191397-multiple-clinical-indications-of-mifepristone-a-systematic-review#!/