Radiation to the Whole Pituitary Compartment Effective at Controlling Cushing’s

Radiation therapy targeting the entire sella — the compartment where the pituitary gland resides at the base of the brain — is effective at controlling Cushing’s disease and should be considered for patients with suspected invasive adenoma tumors, a new study shows.

The study, “Technique of Whole-Sellar Stereotactic Radiosurgery for Cushing’s Disease: Results from a Multicenter, International Cohort Study,” was published in the journal World Neurosurgery.

In patients with Cushing’s disease, excess cortisol levels are caused by a kind of pituitary tumor (adenoma)  that secretes too much adrenocorticotropic hormone (ACTH).

Removing the adenoma using the transsphenoidal approach — a minimally invasive procedure performed through the nose to remove pituitary tumors — remains the first-line treatment for patients with newly diagnosed Cushing’s syndrome. For patients who fail surgery and medical management, stereotactic radiosurgery (SRS) may be used.

SRS is not a surgery in the traditional sense, as it does not require an incision. Instead, SRS uses many focused radiation beams to treat tumors and other problems in the brain, neck and other parts of the body.

While surgery may achieve very good remission rates in patients with an identifiable adenoma, as many as 50 percent of Cushing’s disease patients have no identifiable adenoma on magnetic resonance imaging (MRI) scans. In such cases, surgeons can opt for SRS targeting the entire sella, a procedure called whole-sellar SRS. However, the outcomes of whole-sellar SRS are not fully known.

Researchers conducted an international, retrospective study to analyze the outcomes of Cushing’s disease patients who received whole-sellar SRS.

The study enrolled 68 patients, including 52 who received the procedure for persistent disease, nine whose disease returned after surgery, and seven as their initial treatment.

Patients underwent a type of SRS known as gamma knife radiosurgery (GKRS), which uses small beams of gamma rays to target and treat brain tumors. They were then followed for a mean of 5.3 years.

Whole-sellar SRS was effective at controlling the disease, researchers found. In the five years after receiving the treatment, 75.9 percent of patients achieved a remission. Of those, 86% remained recurrence-free for five or more years.

The mean volume of area targeted using whole-sellar SRS was 2.6 cm3. Researchers discovered that treatment volumes greater than 1.6 cm3 were associated with a shorter time to remission, indicating that targeting a larger portion is more beneficial.

Also, statistical analysis revealed that a reduced dose of radiation was linked to recurrence, suggesting that a higher dose is more advantageous.

Regarding adverse events, 22.7% of patients who underwent whole-sellar SRS developed loss of one or more pituitary hormones.

Researchers also compared outcomes of patients who underwent whole-sellar SRS to those who received adenoma-targeted SRS, of which the latter involves irradiating only the tumor.

Interestingly, there were no differences in remission rate, time to remission, recurrence-free survival, or new endocrine disease development between both groups.

“Whole-sellar GKRS is effective at controlling [Cushing’s disease] when an adenoma is not clearly defined on imaging or when an invasive adenoma is suspected at the time of initial surgery,” the researchers concluded.

From https://cushingsdiseasenews.com/2018/05/25/precise-radiation-pituitary-sella-effective-control-cushings-study/

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/

Etomidate Found Effective in Severe Cushing’s Syndrome

Etomidate — a steroid synthesis blocker — is an effective treatment for patients with severe Cushing’s syndrome who do not respond to ketoconazole, according to a new case report from Mexico.

The report, “Etomidate in the control of severe Cushing’s syndrome by neuroendocrine carcinoma,” appeared in the journal Clinical Case Reports.

The investigators reported the case of a 51-year-old woman with ectopic Cushing’s syndrome caused by a pancreatic tumor. Ectopic Cushing’s refers to cases of excess secretion of adrenocorticotropin hormone (ACTH) outside the pituitary or adrenal glands.

The patient underwent distal pancreatectomy — the surgical removal of the bottom half of the pancreas — in 2015 due to an ACTH-secreting tumor. Although she had a good initial response, liver metastasis was evident by 2016.

Compared to measurements in 2016, morning blood cortisol, 24-hour urinary-free cortisol, and ACTH levels significantly increased in 2017. The patient also showed low levels of the luteinizing and follicle-stimulating hormones, which the scientists attributed to her severe hypercortisolism (excess cortisol levels).

The woman was being treated with ketoconazole to lower her cortisol values and later received chemoembolization — a method to reduce blood supply and deliver chemotherapy directly to a tumor — for her liver metastasis.

Although ketoconazole is generally the treatment of choice for the control of hormone production in the adrenal glands, its effectiveness is often limited and is associated with side effects, clinicians noted.

In April 2017, the patient arrived at the emergency room with sepsis — a potentially life-threatening complication of an infection — that originated in the gut.

Because ketoconazole had failed to lower cortisol levels, the patient started receiving infused etomidate, an inhibitor of the enzyme 11‐beta‐hydroxylase that prevents cortisol synthesis.

This treatment was stopped one day before the bilateral removal of the adrenal glands as a definitive treatment for the elevated production of cortisol.

While the patient experienced decreased levels of potassium, calcium, and magnesium with an initial dose of 0.04 mg per kg body weight an hour of etomidate, a gradual decrease of etomidate — depending on her cortisol levels — corrected these alterations.

After surgery, the patient showed a significant improvement in her general health, including control of her sepsis. She is currently taking hydrocortisone and fludrocortisone, with treatment for liver metastasis pending.

“Etomidate is a very effective drug in severe Cushing’s syndrome that is refractory to ketoconazole,” the researchers wrote.

“Control of the serum cortisol levels in ectopic Cushing’s syndrome can be obtained with infusion rates much lower than those used in anesthesia, without respiratory side effects,” they added.

The authors recommend an initial dose of etomidate of 0.04 mg/kg per hour, daily monitoring of 24-hour urinary cortisol and cortisol levels, and a gradual decrease of the etomidate dose according to daily measurements of metabolites.

From https://cushingsdiseasenews.com/2018/05/17/severe-cushings-syndrome-case-study-finds-etomidate-effective-therapy/

Study Describes 6 Common Surgical Failures in Cushing’s Disease Treatment

To help improve the effectiveness of surgical treatment of Cushing’s disease, researchers conducted a study to determine common failures. They classified these failures into six different categories.

Results were reported in the study, “Root cause analysis of diagnostic and surgical failures in the treatment of suspected Cushing’s disease,” published in the Journal of Clinical Neuroscience.

The surgical removal of lesions that secrete excess adrenocorticotropic hormone (ACTH) is the first line of treatment for patients with Cushing’s disease. But while this approach is effective in reducing cortisol levels, up to 31 percent of patients fail to achieve remission.

When initial surgery is ineffective, additional surgical procedures may help to improve patient outcomes. Medications also are used for those who do not see results from surgery.

Recognizing the factors that contribute to the failure of surgical treatment is crucial to avoiding a deterioration of patient health and to improving long-term outcomes.

Researchers at Harvard Medical School examined the clinical records of 51 patients suspected of having Cushing’s disease. These patients were followed and surgically treated at the Brigham and Women’s Hospital in Boston, from April 2008 to July 2017.

In more than 82 percent of the cases, tissue removed during surgery confirmed that the patients had excess ACTH caused by benign tumors in the adrenal gland. Among the remaining patients, two had additional ACTH-secreting tumors, four had no obvious tumor or abnormal tissue, one had a pituitary mass without ACTH secretion, and one had no evidence of tissue changes despite the detection of a tumor during exploratory surgery.

They were followed for an average of 18.3 months, during which 42 patients achieved remission as confirmed by blood tests. Of these, 34 patients did not require additional treatment; four patients needed additional surgeries to achieve control over cortisol levels; and four patients required additional radiosurgery.

Based on long-term patient outcomes, researchers were able to identify six categories of common diagnostic and surgical failures. They include:

  • persistently high cortisol levels despite the successful removal of lesions
  • the failure of tumor resection
  • recurrence of disease
  • a failure to identify the source of ACTH secretion
  • the absence of identifiable lesions during exploratory surgery
  • concurrent tumors.

While the first three are common among patients with a visible lesion on imaging scans, the latter three are characteristic of patients in whom physicians fail to detect a lesion.

Investigators believe that anticipating and recognizing these common failures may help to improve the effectiveness of surgery, symptom management, and overall treatment outcomes.

“The success of surgical intervention can be enhanced greatly by improving patient selection and surgical management by anticipating and subsequently deterring the six common failures described above,” the team concluded. They added that better imaging methods also might improve outcomes for Cushing’s disease patients.

From https://cushingsdiseasenews.com/2018/05/15/cushings-disease-surgery-6-common-failures-found-retrospective-study/

Relacorilant Effectively Manages Cortisol Effects in Cushing’s Patients

Relacorilant, an investigational therapy developed by Corcept Therapeutics, may effectively manage the effects of excess cortisol in patients with Cushing’s syndrome, interim data from an ongoing Phase 2 trial show.

In particular, the treatment significantly improved sugar tolerance and the levels of osteocalcin, a bone growth biomarker  commonly suppressed by excess cortisol.

Corcept announced in a press release that the trial (NCT02804750) has completed patient enrollment. Results from the first patients will be presented during the upcoming 27th American Association of Clinical Endocrinologists (AACE) annual meeting, May 16-20 in Boston. Full data is expected by the third quarter of 2018.

Relacorilant, also known as CORT125134, was designed to prevent the effects of excess cortisol by blocking one of its receptors, the glucocorticoid receptor.

In a Phase 1 trial with healthy volunteers, multiple doses of relacorilant had a similar effect as Korlym (mifepristone) — an approved medicine for Cushing’s patients — without its known side effects.

In addition to the early efficacy data, the study showed that the treatment was generally safe and well-tolerated by the patients, with adverse events reportedly mild in severity.

These findings supported the launch of the Phase 2 trial in patients with Cushing’s syndrome. In the trial, roughly 30 patients are receiving escalating doses of relacorilant for a total of 12 weeks.

Patients were divided into two groups. The first group, which includes 17 patients, receives the lowest dose — 100 mg/day of relacorilant for four weeks, followed by 150 mg/day for four weeks, and then 200 mg/day for the last four weeks. The second group, called the high-dose cohort, is treated with a similar regimen but with a starting dose of 250 mg/day and a final dose of 350 mg/day.

Patients in the low-dose group had a significant improvement in their glucose tolerance and a 60% increase in blood osteocalcin.

In addition, the treatment reduced the blood pressure in 45% of patients with uncontrolled high blood pressure from cortisol excess. Importantly, the results after 12 weeks of relacorilant were similar to those seen after six months of Korlym treatment.

Safety data continues to show a positive profile, with no evidence of serious adverse effects and no affinity toward the progesterone receptor, which is a major drawback of Korlym.

“Relacorilant’s clinical results are striking because the doses these patients received were the study’s lowest. We did not expect patients to experience any meaningful clinical benefit, but they clearly did,” Robert S. Fishman, MD, chief medical officer of Corcept, said in the release. “We look forward to presenting data from these low-dose patients at the AACE meeting next week. With the trial’s final, high-dose cohort fully enrolled, we will have final data in the third quarter.”

Supported by these preliminary data, Corcept has accelerated the preparations for a Phase 3 trial on relacorilant in Cushing’s syndrome patients.

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