Characterization of persistent and recurrent Cushing’s disease

Pituitary, 09/25/2013  Review Article

Sundaram NK et al. – A case of possible recurrent Cushing’s disease (CD) is presented and data on current definitions of CD remission, persistence, and recurrence are reviewed.

The number and degree of abnormal test results needed to define recurrence, and the determination of which biochemical test has more significance when there are discrepancies between markers is inconsistent among studies. Further inquiry is warranted to examine if patients in apparent CD remission who have subtle hypothalamic pituitary adrenal (HPA) axis abnormalities represent distinctive remission subtypes versus mild or early recurrence.

Additional investigation could also explore the degree to which these HPA axis abnormalities, such as alterations in cortisol circadian rhythm or partial resistance to dexamethasone, are associated with persistence of CD morbidities, including neuropsychiatric impairments, alterations in body composition, and cardiovascular risk.

From MDLinx

Cushing’s Disease – Rare Disease Quick Facts

cushings-diagnosis

 

 

Cushing’s disease is a rare condition due to excess cortisol levels that result from a pituitary tumor secreting adrenocorticotropic hormone (ACTH), which stimulates cortisol secretion.  Cushing’s disease should not be confused with Cushing’s syndrome which is increased cortisol levels but that increase can be due to any number of factors. However, Cushing’s disease is the most common form of Cushing’s syndrome.

Symptoms

The symptoms related to Cushing’s disease and Cushing’s syndrome are the same, since both are related to an excess of cortisol. Also, symptoms vary extensively among patients and that, with the inherent fluctuation in hormone levels make it difficult to diagnosis both conditions.

Changes in physical characteristics of the body

  • Fullness and rounding of the face
  • Added fat on back of neck (so-called “buffalo hump”)
  • Easy bruising
  • Purplish stretch marks on the abdomen (abdominal striae)
  • Excessive weight gain, especially in abdominal region
  • Red cheeks
  • Excess hair growth on the face, neck, chest, abdomen and thighs

Changes in physiology/psychology

  • Generalized weakness and fatigue
  • Menstrual disorder
  • Decreased fertility and/or sex drive
  • High blood pressure that is often difficult to treat
  • Diabetes mellitus
  • Mood and behavior disorders

Diagnosis

The early stages of Cushing’s disease may be difficult to recognize. However, if it is suspected, diagnosis is generally a 2 stage process. First to determine if cortisol levels are high, and if so, why they are high.

Tests to confirm high cortisol levels:

  • 24-hour urine cortisol
  • Dexamethasone suppression test (low dose)

Tests to determine cause:

  • Blood ACTH level
  • Brain MRI
  • Corticotropin-releasing hormone test
  • Dexamethasone suppression test (high dose)
  • Petrosal sinus sampling

Treatment

Surgery

  • Most patients with Cushing’s disease undergo surgery to remove the pituitary adenoma offers.
  • If the tumor is isolated to the pituitary, cure rates of 80-85% are common.
  • If the tumor has spread to nearby organs, cure rates of 50-55% are common.

Medicine (approved orphan drugs)

Signifor (pasireotide)

  • Approved for patients with Cushing’s disease for whom pituitary is not an option or surgery has been ineffective.
  • Signifor is a somatostatin receptor agonist that leads to inhibition of ACTY secretion (and subsequently decreased cortisol levels).

Korlym (mifepristone)

  • Approved for patients with Cushing’s syndrome who have type 2 diabetes or glucose intolerance and have failed surgery (or not candidates for surgery).
  • Korlym is a glucocorticoid receptor antagonist which in turn blocks the effects of the high levels of cortisol in the body. Korlym is used to treat high glucose levels due to elevated cortisol.

Medicines used but not indicated for Cushing’s disease include

Mitoden

ketoconazole

Metyrapone

Etomidate

Radiation

  • Radiation therapy may be used in some patients and can be very effective in controlling the growth of these tumors.

Prognosis

In most cases, treatment can cure Cushing’s disease. If not treated properly, the chronic hypercortisolism can lead to excess morbidity and mortality due to increased cardiovascular and other risk factors.

For more information

National Library of Medicine, National Institute of Health

Cushing’s Disease Information (provided by Novartis Pharmaceuticals)

 

Images courtesy of the open access journal Orhanet Journal for Rare Diseases.  Castinetti et al. Orphanet J Rare Dis. 2012 7:41   doi:10.1186/1750-1172-7-41

– See more at: http://www.raredr.com/front-page-medicine/articles/cushings-disease-rare-disease-quick-facts-0

Pituitary tumor size not definitive for Cushing’s

By: SHERRY BOSCHERT, Family Practice News Digital Network

SAN FRANCISCO – The size of a pituitary tumor on magnetic resonance imaging in a patient with ACTH-dependent Cushing’s syndrome can’t differentiate between etiologies, but combining that information with biochemical test results could help avoid costly and difficult inferior petrosal sinus sampling in some patients, a study of 131 cases suggests.

If MRI shows a pituitary tumor larger than 6 mm in size, the finding is 40% sensitive and 96% specific for a diagnosis of Cushing’s disease as the cause of adrenocorticotropic hormone (ACTH)-dependent Cushing’s syndrome, and additional information from biochemical testing may help further differentiate this from ectopic ACTH secretion, Dr. Divya Yogi-Morren and her associates reported at the Endocrine Society’s Annual Meeting.

Pituitary tumors were seen on MRI in 6 of 26 patients with ectopic ACTH secretion (23%) and 73 of 105 patients with Cushing’s disease (69%), with mean measurements of 4.5 mm in the ectopic ACTH secretion group and 8 mm in the Cushing’s disease group. All but one tumor in the ectopic ACTH secretion group were 6 mm or smaller in diameter, but one was 14 mm.

Because pituitary “incidentalomas” as large as 14 mm can be seen in patients with ectopic ACTH secretion, the presence of a pituitary tumor can’t definitively discriminate between ectopic ACTH secretion and Cushing’s disease, said Dr. Yogi-Morren, a fellow at the Cleveland Clinic.

That finding contradicts part of a 2003 consensus statement that said the presence of a focal pituitary lesion larger than 6 mm on MRI could provide a definitive diagnosis of Cushing’s disease, with no further evaluation needed in patients who have a classic clinical presentation and dynamic biochemical testing results that are compatible with a pituitary etiology (J. Clin. Endocrinol. Metab. 2003;88:5593-602). The 6-mm cutoff, said Dr. Yogi-Morren, came from an earlier study reporting that 10% of 100 normal, healthy adults had focal pituitary abnormalities on MRI ranging from 3 to 6 mm in diameter that were consistent with a diagnosis of asymptomatic pituitary adenomas (Ann. Intern. Med. 1994;120:817-20).

A traditional workup of a patient with ACTH-dependent Cushing’s syndrome might include a clinical history, biochemical testing, neuroimaging, and an inferior petrosal sinus sampling (IPSS). Biochemical testing typically includes tests for hypokalemia, measurement of cortisol and ACTH levels, a high-dose dexamethasone suppression test, and a corticotropin-releasing hormone (CRH) stimulation test. Although IPSS is the gold standard for differentiating between the two etiologies, it is expensive and technically difficult, especially in institutions that don’t regularly do the procedure, so it would be desirable to avoid IPSS if it’s not needed in a subset of patients, Dr. Yogi-Morren said.

The investigators reviewed charts from two centers (the Cleveland Clinic and the M.D. Anderson Cancer Center, Houston) for patients with ACTH-dependent Cushing’s syndrome seen during 2000-2012.

ACTH levels were significantly different between groups, averaging 162 pg/mL (range, 58-671 pg/mL) in patients with ectopic ACTH secretion, compared with a mean 71 pg/mL in patients with Cushing’s disease (range, 16-209 pg/mL), she reported. Although there was some overlap between groups in the range of ACTH levels, all patients with an ACTH level higher than 210 pg/mL had ectopic ACTH secretion.

Median serum potassium levels at baseline were 2.9 mmol/L in the ectopic ACTH secretion group and 3.8 mmol/L in the Cushing’s disease group, a significant difference. Again, there was some overlap between groups in the range of potassium levels, but all patients with a baseline potassium level lower than 2.7 mmol/L had ectopic ACTH secretion, she said.

Among patients who underwent a high-dose dexamethasone suppression test, cortisol levels decreased by less than 50% in 88% of patients with ectopic ACTH secretion and in 26% of patients with Cushing’s disease.

Most patients did not undergo a standardized, formal CRH stimulation test, so investigators extracted the ACTH response to CRH in peripheral plasma during the IPSS test. As expected, they found a significantly higher percent increase in ACTH in response to CRH during IPSS in the Cushing’s disease group, ranging up to more than a 1,000% increase. In the ectopic ACTH secretion group, 40% of patients did have an ACTH increase greater than 50%, ranging as high as a 200%-300% increase in ACTH in a couple of patients.

“Although there was some overlap in the biochemical testing, it is possible that it provides some additional proof to differentiate between ectopic ACTH secretion and Cushing’s disease,” Dr. Yogi-Morren said.

In the ectopic ACTH secretion group, the source of the secretion remained occult in seven patients. The most common identifiable cause was a bronchial carcinoid tumor, in six patients. Three patients each had small cell lung cancer, a thymic carcinoid tumor, or a pancreatic neuroendocrine tumor. One patient each had a bladder neuroendocrine tumor, ovarian endometrioid cancer, medullary thyroid cancer, or a metastatic neuroendocrine tumor from an unknown primary cancer.

The ectopic ACTH secretion group had a median age of 41 years and was 63% female. The Cushing’s disease group had a median age of 46 years and was 76% female.

Dr. Yogi-Morren reported having no financial disclosures.

sboschert@frontlinemedcom.com

On Twitter @sherryboschert

From Famiiy Practice News

Early Detection, Treatment Needed To Reduce Risk Of Death, Cardiovascular Disease In Cushing’s Disease Patients

Even after successful treatment, patients with Cushing’s disease who were older when diagnosed or had prolonged exposure to excess cortisol face a greater risk of dying or developing cardiovascular disease, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

Cushing’s disease is a rare condition where the body is exposed to excess cortisol – a stress hormone produced in the adrenal gland – for long periods of time.

Researchers have long known that patients who have Cushing’s disease are at greater risk of developing and dying from cardiovascular disease than the average person. This study examined whether the risk could be eliminated or reduced when the disease is controlled. Researchers found that these risk factors remained long after patients were exposed to excess cortisol.

“The longer patients with Cushing’s disease are exposed to excess cortisol and the older they are when diagnosed, the more likely they are to experience these challenges,” said Eliza B. Geer, MD, of Mount Sinai Medical Center and lead author of the study. “The findings demonstrate just how critical it is for Cushing’s disease to be diagnosed and treated quickly. Patients also need long-term follow-up care to help them achieve good outcomes.”

The study found cured Cushing’s disease patients who had depression when they started to experience symptoms of the disease had an elevated risk of mortality and cardiovascular disease. Men were more at risk than women, a trend that may be explained by a lack of follow-up care, according to the study. In addition, patients who had both Cushing’s syndrome and diabetes were more likely to develop cardiovascular disease.

The study examined one of the largest cohorts of Cushing’s disease patients operated on by a single surgeon. The researchers retrospectively reviewed charts for 346 Cushing’s disease patients who were treated between 1980 and 2011. Researchers estimated the duration of exposure to excess cortisol by calculating how long symptoms lasted before the patient went into remission. The patients who were studied had an average exposure period of 40 months.

The findings may have implications for people who take steroid medications, Geer said. People treated with high doses of steroid medications such as prednisone, hydrocortisone or dexamethasone are exposed to high levels of cortisol and may experience similar conditions as Cushing’s disease patients.

“While steroid medications are useful for treating patients with a variety of conditions, the data suggests health care providers need to be aware that older patients or those who take steroid medications for long periods could be facing higher risk,” Geer said. “These patients should be monitored carefully while more study is done in this area.”

From http://www.medicalnewstoday.com/releases/256284.php