ACTH Levels After Surgery Help Predict Remission, Recurrence in Cushing’s

Levels of adrenocorticotropic hormone (ACTH) in circulation after pituitary surgery may help predict which Cushing’s disease patients will achieve early remission and which will eventually see the disease return, a study shows.

Also, the earlier that patients reached their lowest peak of ACTH levels, the better their long-term outcomes.

The study, “Prognostic usefulness of ACTH in the postoperative period of Cushing’s disease,” was published in the journal Endocrine Connections.

Removing the pituitary tumor through a minimally invasive surgery called transsphenoidal surgery is still the treatment of choice for Cushing’s disease patients. But not all patients enter remission, and even among those who do, a small proportion will experience disease recurrence.

While cortisol levels have been suggested as a main predictor of remission and recurrence, there is no consensus as to which cutoff point should be used after surgery, or the best time for measuring this hormone.

Because Cushing’s disease is caused by an ACTH-producing tumor in the pituitary gland, and ACTH has a short half-life (approximately 10 minutes), it is expected that ACTH levels drop markedly within a few hours after surgery.

Thus, a group of researchers in Spain aimed to determine whether blood levels of ACTH could be useful for predicting remission of Cushing’s disease both immediately after surgery (defined as less than 72 hours) and in the long term.

Researchers analyzed 65 patients with Cushing’s disease who had undergone transsphenoidal surgery (seven required a second intervention) between 2005 and 2016. Remission within three months was seen in 56 of 65 cases; late disease recurrence was seen in 18 of 58 cases.

Investigators measured the ACTH nadir concentration (defined as the lowest concentration) and the time taken to reach nadir levels after surgery, as well as the plasma ACTH concentration before hospital discharge.

While ACTH levels had no predictive value, the team found that people who went into remission had significantly lower ACTH nadir levels and ACTH levels at discharge. On the other hand, levels of ACHT nadir and at discharge were significantly higher for people who experienced a relapse, compared to those who remained in remission.

Using artificial intelligence algorithms, the researchers further found that ACTH nadir, ACTH at discharge, and cortisol nadir values were all of great relevance to predict remission within three months.

Analysis indicated that using a cutoff point of 3.3 pmol/L of ACTH after surgery and before discharge gave the best sensitivity and specificity for predicting a patient’s prognosis.

Researchers further found that the time patients took to reach their ACTH nadir, regardless of nadir levels, also influenced their outcomes. In fact, patients reaching this nadir in less than than 46 hours more likely achieved early remission.

And taking longer than 39 hours to reach the ACTH nadir was significantly more frequent in patients who experienced recurrence. This indicates that the time to ACTH nadir is an important measure for prognosis.

“In the immediate postoperative period of patients with [Cushing’s disease], the ACTH concentration is of prognostic utility in relation to late disease remission,” the researchers said.

Overall, “we propose an ACTH value <3.3 pmol/L as a good long-term prognostic marker in the postoperative period of CD. Reaching the ACTH nadir in less time is associated to a lesser recurrence rate,” the study concluded.

Patricia holds her Ph.D. in Cell Biology from University Nova de Lisboa, and has served as an author on several research projects and fellowships, as well as major grant applications for European Agencies. She also served as a PhD student research assistant in the Laboratory of Doctor David A. Fidock, Department of Microbiology & Immunology, Columbia University, New York.

New discoveries offer possible Cushing’s disease cure

LOS ANGELES — More than a century has passed since the neurosurgeon and pathologist Harvey Cushing first discovered the disease that would eventually bear his name, but only recently have several key discoveries offered patients with the condition real hope for a cure, according to a speaker here.

There are several challenges clinicians confront in the diagnosis and treatment of Cushing’s disease, Shlomo Melmed, MB, ChB, FRCP, MACP, dean, executive vice president and professor of medicine at Cedars-Sinai Medical Center in Los Angeles, said during a plenary presentation. Patients who present with Cushing’s disease typically have depression, impaired mental function and hypertension and are at high risk for stroke, myocardial infarction, thrombosis, dyslipidemia and other metabolic disorders, Melmed said. Available therapies, which range from surgery and radiation to the somatostatin analogue pasireotide (Signifor LAR, Novartis), are often followed by disease recurrence. Cushing’s disease is fatal without treatment; the median survival if uncontrolled is about 4.5 years, Melmed said.

“This truly is a metabolic, malignant disorder,” Melmed said. “The life expectancy today in patients who are not controlled is apparently no different from 1930.”

The outlook for Cushing’s disease is now beginning to change, Melmed said. New targets are emerging for treatment, and newly discovered molecules show promise in reducing the secretion of adrenocorticotropic hormone (ACTH) and pituitary tumor size.

“Now, we are seeing the glimmers of opportunity and optimism, that we can identify specific tumor drivers — SST5, [epidermal growth factor] receptor, cyclin inhibitors — and we can start thinking about personalized, precision treatment for these patients with a higher degree of efficacy and optimism than we could have even a year or 2 ago,” Melmed said. “This will be an opportunity for us to broaden the horizons of our investigations into this debilitating disorder.”

Challenges in diagnosis, treatment

Overall, about 10% of the U.S. population harbors a pituitary adenoma, the most common type of pituitary disorder, although the average size is only about 6 mm and 40% of them are not visible, Melmed said. In patients with Cushing’s disease, surgery is effective in only about 60% to 70% of patients for initial remission, and overall, there is about a 60% chance of recurrence depending on the surgery center, Melmed said. Radiation typically leads to hypopituitarism, whereas surgical or biochemical adrenalectomy is associated with adverse effects and morbidity. Additionally, the clinical features of hypercortisolemia overlap with many common illnesses, such as obesity, hypertension and type 2 diabetes.

“There are thousands of those patients for every patient with Cushing’s disease who we will encounter,” Melmed said.

The challenge for the treating clinician, Melmed said, is to normalize cortisol and ACTH with minimal morbidity, to resect the tumor mass or control tumor growth, preserve pituitary function, improve quality of life and achieve long-term control without recurrence.

“This is a difficult challenge to meet for all of us,” Melmed said.

Available options

Pituitary surgery is typically the first-line option offered to patients with Cushing’s disease, Melmed said, and there are several advantages, including rapid initial remission, a one-time cost and potentially curing the disease. However, there are several disadvantages with surgery; patients undergoing surgery are at risk for postoperative venous thromboembolism, persistent hypersecretion of ACTH, adenoma persistence or recurrence, and surgical complications.

Second-line options are repeat surgery, radiation, adrenalectomy or medical therapy, each with its own sets of pros and cons, Melmed said.

“The reality of Cushing’s disease — these patients undergo first surgery and then recur, second surgery and then recur, then maybe radiation and then recur, and then they develop a chronic illness, and this chronic illness is what leads to their demise,” Melmed said. “Medical therapy is appropriate at every step of the spectrum.”

Zebrafish clues

Searching for new options, Melmed and colleagues introduced a pituitary tumor transforming gene discovered in his lab into zebrafish, which caused the fish to develop the hallmark features of Cushing’s disease: high cortisol levels, diabetes and cardiovascular disease. In the fish models, researchers observed that cyclin E activity, which drives the production of ACTH, was high.

Melmed and colleagues then screened zebrafish larvae in a search for cyclin E inhibitors to derive a therapeutic molecule and discovered R-roscovitine, shown to repress the expression of proopiomelanocortin (POMC), the pituitary precursor of ACTH.

In fish, mouse and in vitro human cell models, treatment with R-roscovitine was associated with suppressed corticotroph tumor signaling and blocked ACTH production, Melmed said.

“Furthermore, we asked whether or not roscovitine would actually block transcription of the POMC gene,” Melmed said. “It does. We had this molecule (that) suppressed cyclin E and also blocks transcription of POMC leading to blocked production of ACTH.”

In a small, open-label, proof-of-principal study, four patients with Cushing’s disease who received roscovitine for 4 weeks developed normalized urinary free cortisol, Melmed said.

Currently, the FDA Office of Orphan Products Development is funding a multicenter, phase 2, open-label clinical trial that will evaluate the safety and efficacy of two of three potential doses of oral roscovitine (seliciclib) in patients with newly diagnosed, persistent or recurrent Cushing disease. Up to 29 participants will be treated with up to 800 mg per day of oral seliciclib for 4 days each week for 4 weeks and enrolled in sequential cohorts based on efficacy outcomes.

“Given the rarity of the disorder, it will probably take us 2 to 3 years to recruit patients to give us a robust answer,” Melmed said. “This zebrafish model was published in 2011, and we are now in 2019. It has taken us 8 years from publication of the data to, today, going into humans with Cushing’s. Hopefully, this will light the pathway for a phase 2 trial.”

 Offering optimism’

Practitioners face a unique paradigm when treating patients with Cushing’s disease, Melmed said. Available first- and second-line therapy options often are not a cure for many patients, who develop multimorbidity and report a low quality of life.

“Then, we are kept in this difficult cycle of what to do next and, eventually, running out of options,” Melmed said. “Now, we can look at novel, targeted molecules and add those to our armamentarium and at least offer our patients the opportunity to participate in trials, or at least offer the optimism that, over the coming years, there will be a light at the end of the tunnel for their disorder.”

Melmed compared the work to Lucas Cranach’s Fons Juventutis (The Fountain of Youth). The painting, completed in 1446, shows sick people brought by horse-drawn ambulance to a pool of water, only to emerge happy and healthy.

“He was imagining this ‘elixir of youth’ (that) we could offer patients who are very ill and, in fact, that is what we as endocrinologists do,” Melmed said. “We offer our patients these elixirs. These Cushing’s patients are extremely ill. We are trying with all of our molecular work and our understanding of pathogenesis and signaling to create this pool of water for them, where they can emerge with at least an improved quality of life and, hopefully, a normalized mortality. That is our challenge.” – by Regina Schaffer

Reference:

Melmed S. From zebrafish to humans: translating discoveries for the treatment of Cushing’s disease. Presented at: AACE Annual Scientific and Clinical Congress; April 24-28, 2019; Los Angeles.

Disclosure: Melmed reports no relevant financial disclosures.

 

From https://www.healio.com/endocrinology/neuroendocrinology/news/online/%7B585002ad-640f-49e5-8d62-d1853154d7e2%7D/new-discoveries-offer-possible-cushings-disease-cure

Faster Adrenal Recovery May Predict Cushing’s Disease Recurrence

A shorter duration of adrenal insufficiency — when the adrenal gland is not working properly — after surgical removal of a pituitary tumor may predict recurrence in Cushing’s disease patients, a new study suggests.

The study, “Recovery of the adrenal function after pituitary surgery in patients with Cushing Disease: persistent remission or recurrence?,” was published in the journal Neuroendocrinology.

Cushing’s disease is a condition characterized by excess cortisol in circulation due to a tumor in the pituitary gland that produces too much of the adrenocorticotropic hormone (ACTH). This hormone acts on the adrenal glands, telling them to produce cortisol.

The first-line treatment for these patients is pituitary surgery to remove the tumor, but while success rates are high, most patients experience adrenal insufficiency and some will see their disease return.

Adrenal insufficiency happens when the adrenal glands cannot make enough cortisol — because the source of ACTH was suddenly removed — and may last from months to years. In these cases, patients require replacement hormone therapy until normal ACTH and cortisol production resumes.

However, the recovery of adrenal gland function may mean one of two things: either patients have their hypothalamus-pituitary-adrenal axis — a feedback loop that regulates ACTH and cortisol production — functioning normally, or their disease returned.

So, a team of researchers in Italy sought to compare the recovery of adrenal gland function in patients with a lasting remission to those whose disease recurred.

The study included 61 patients treated and followed at the Ospedale Maggiore Policlinico of Milan between 1990 and 2017. Patients had been followed for a median of six years (minimum three years) and 10 (16.3%) saw their disease return during follow-up.

Overall, the median time to recovery of adrenal function was 19 months, but while most patients in remission (67%) had not yet recovered their adrenal function after a median of six years, all patients whose disease recurred experienced adrenal recovery within 22 months.

Among those with disease recurrence, the interval from adrenal recovery to recurrence lasted a median of 1.1 years, but in one patient, signs of disease recurrence were not seen for 15.5 years.

Statistical analysis revealed that the time needed for adrenal recovery was negatively associated with disease recurrence, suggesting that patients with sorter adrenal insufficiency intervals were at an increased risk for recurrence.

“In conclusion, our study shows that the duration of adrenal insufficiency after pituitary surgery in patients with CD is significantly shorter in recurrent CD than in the persistent remission group,” researchers wrote.

“The duration of AI may be a useful predictor for CD [Cushing’s disease] recurrence and those patients who show a normal pituitary-adrenal axis within 2 years after surgery should be strictly monitored being more at risk of disease relapse,” they concluded.

From https://cushingsdiseasenews.com/2019/01/29/faster-adrenal-recovery-may-predict-recurrence-cushings-disease/

Endoscopic Surgery Should Be Standard for Cushing’s Patients with Large Tumors

Cushing’s disease patients with macroadenomas — pituitary tumors larger than 10 mm — should undergo transsphenoidal pituitary surgery using the endoscopic technique, according to a new systematic review.

The study, “Endoscopic vs. microscopic transsphenoidal surgery for Cushing’s disease: a systematic review and meta-analysis,” was published in the journal Pituitary.

Cushing’s disease develops due to an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma. The first-choice treatment for Cushing’s disease is transsphenoidal pituitary surgery, which is performed through the nose to remove pituitary tumors.

There are two main methods to conduct this kind of surgery: microscopic, which is done using a magnifying tool, and endoscopic surgery, which uses a thin, lighted tube with a tiny camera. The microscopic technique was the established method for transsphenoidal surgery, until physicians started doing endoscopic pituitary surgery in 1992.

Most surgical centers choose to perform either the microscopic or endoscopic technique but do not offer both. As a result, only a few small studies have compared the outcomes of microscopic and endoscopic surgical techniques in Cushing’s disease performed at the same center. These studies showed no clear differences in remission rates or surgical morbidity.

To date, no systematic review comparing the microscopic and the endoscopic surgical techniques in Cushing’s disease has been conducted and, therefore, convincing evidence to support either technique is lacking.

To address this, researchers set out to conduct a systematic review and meta-analysis that compares the endoscopic and microscopic transsphenoidal surgery techniques for Cushing’s disease with regards to surgical outcomes and complication rates.

Researchers searched through nine electronic databases to identify potentially relevant articles. In total, 97 cohort studies with 6,695 patients were included in the study. Among the total patient population, 5,711 received microscopical surgery and 984 were endoscopically operated.

Overall remission was achieved in 80 percent of patients, with no clear differences between the techniques. The recurrence rate was around 10 percent, and short-term mortality was less than 0.5 percent.

Cerebrospinal fluid leak (due to a hole or a tear) occurred more often in patients who underwent endoscopic surgery. On the other hand, transient diabetes insipidus — short-term diabetes — occurred more often in patients who received endoscopic surgery.

When classifying patients by tumor size, however, researchers found that patients with macroadenomas — tumors larger than 10 mm — had higher rates of remission and lower recurrence rates after endoscopic surgery. Patients with microadenomas (tumors smaller than 10 mm) had comparable outcomes with either technique.

“Endoscopic surgery for patients with Cushing’s disease reaches comparable results for microadenomas, and probably better results for macroadenomas than microscopic surgery,” the investigators wrote.

Taking these results into account, the researchers suggest that endoscopic surgery may be considered the current standard of care, though microscopic surgery can be used based on the neurosurgeon’s preference.

They also emphasize that centers that solely perform the microscopic technique should consider at least referring Cushing’s disease patients with macroadenomas to a center that performs the endoscopic technique.

From https://cushingsdiseasenews.com/2018/05/24/endoscopic-surgery-more-effective-macroadenomas-cushings-study/

High Levels of MMP-9 Enzyme May Predict Tumor Recurrence in Cushing’s Patients

Measuring the levels of a specific enzyme in pituitary tumors producing excess adrenocorticotrophic hormone (ACTH) may help predict the recurrence of Cushing’s disease in patients, a study shows.

The study, “Expression of MMP-9, PTTG, HMGA2, and Ki-67 in ACTH-secreting pituitary tumors and their association with tumor recurrence,” was published in the journal World Neurosurgery.

Cushing’s syndrome is characterized by excess cortisol levels in the blood. In 70 percent of cases, this is caused by pituitary tumors making too much ACTH, a hormone that regulates cortisol production. This condition is called Cushing’s disease.

While transsphenoidal adenomectomy, a surgery to remove a pituitary gland tumor, is the first treatment choice, tumor recurrence rates can be as high as 45 percent.

Only a few studies have investigated the association between biomarkers and the risk of ACTH-secreting pituitary tumors recurring, leaving physicians with limited methods to predict which patients will have a recurrence.

Identifying biomarkers that can effectively predict the potential recurrence of Cushing’s disease would allow clinicians to look for early signs in patients and start appropriate follow-up and therapeutic protocols, avoiding long-term mortality.

Many studies have suggested that matrix metalloproteinase-9 (MMP-9) enzymes, the pituitary tumor transforming gene (PTTG), and high mobility group A 2 proteins (HMGA2) all play vital roles in the development of pituitary tumors.

Metalloproteinases (MMPs) are enzymes that work to degrade the cell’s extracellular matrix, which anchors the cell, thus enabling tumor invasion. PTTG is highly expressed in pituitary tumors, and is a marker of malignancy in many types of tumors. HMGA2 is overexpressed in various tumors, and is also associated with high malignancy.

However, whether levels of MMP-9, PTTG, and HMGA2 are related to ACTH-secreting tumor recurrence has not been investigated.

Researchers set out to determine the expression levels of MMP-9, PTTG, HMGA2, and Ki-67 (a marker of cell growth) in ACTH-secreting pituitary tumors, and evaluate their association with tumor behavior and recurrence.

They conducted a retrospective study that included 55 patients with sporadic Cushing’s disease with long-term remission after a transsphenoidal adenomectomy. Their tumor specimens were collected and examined.

Patients were divided into two groups based on whether or not they had tumor recurrence. There were 28 patients in the non-recurrent group, and 27 in the recurrent.

Results showed there was significantly increased expression of MMP-9 in tumor samples of recurrent patients, compared with the non-recurrent group. Levels of MMP-9 were also strongly associated with a shorter time period to recurrence (recurrence-free interval).

On the other hand, PTTG, HMGA2, and Ki-67 expression was not significantly different between the recurrent group and the non-recurrent group.

“ACTH-secreting pituitary tumors with higher levels of MMP-9 were associated with a higher recurrence rate and a shorter recurrence-free interval. MMP-9 could be a valuable tool for predicting recurrence of ACTH-secreting pituitary tumors,” the researchers concluded.

From https://cushingsdiseasenews.com/2018/03/02/mmp-9-enzyme-levels-may-predict-tumor-recurrence-in-cushings-study/

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