Excess mortality among people with endogenous Cushing’s syndrome (CS) has declined in the past 20 years yet remains three times higher than in the general population, new research finds.
Among more than 90,000 individuals with endogenous CS, the overall proportion of mortality – defined as the ratio of the number of deaths from CS divided by the total number of CS patients – was 0.05, and the standardized mortality rate was an “unacceptable” three times that of the general population, Padiporn Limumpornpetch, MD, reported on March 20 at ENDO 2021: The Endocrine Society Annual Meeting.
Excess deaths were higher among those with adrenal CS, compared with those with Cushing’s disease. The most common causes of death among those with CS were cardiovascular diseases, cerebrovascular accident, infection, and malignancy, noted Dr. Limumpornpetch, of Songkla University, Hat Yai, Thailand, who is also a PhD student at the University of Leeds, United Kingdom.
“While mortality has improved since 2000, it is still significantly compromised compared to the background population ... The causes of death highlight the need for aggressive management of cardiovascular risk, prevention of thromboembolism, infection control, and a normalized cortisol level,” she said.
Asked to comment, Maria Fleseriu, MD, told this news organization that the new data show “we are making improvements in the care of patients with CS and thus outcomes, but we are not there yet ... This meta-analysis highlights the whole spectrum of acute and life-threatening complications in CS and their high prevalence, even before disease diagnosis and after successful surgery.”
She noted that although she wasn’t surprised by the overall results, “the improvement over time was indeed lower than I expected. However, interestingly here, the risk of mortality in adrenal Cushing’s was unexpectedly high despite patients with adrenal cancer being excluded.”
Dr. Fleseriu, who is director of the Pituitary Center at Oregon Health and Science University, Portland, advised, “Management of hyperglycemia and diabetes, hypertension, hypokalemia, hyperlipidemia, and other cardiovascular risk factors is generally undertaken in accordance with standard of clinical care.”
“But we should focus more on optimizing more aggressively this care in addition to the specific Cushing’s treatment,” she stressed.
In addition, she noted, “Medical therapy for CS may be needed even prior to surgery in severe and/or prolonged hypercortisolism to decrease complications ... We definitely need a multidisciplinary approach to address complications and etiologic treatment as well as the reduced long-term quality of life in patients with CS.”
Largest study in scale and scope of Cushing’s syndrome mortality
Endogenous Cushing’s syndrome occurs when the body overproduces cortisol. The most common cause of the latter is a tumor of the pituitary gland (Cushing’s disease), but another cause is a usually benign tumor of the adrenal glands (adrenal Cushing’s syndrome). Surgery is the mainstay of initial treatment of Cushing’s syndrome. If an operation to remove the tumor fails to cause remission, medications are available.
Prior to this new meta-analysis, there had been limited data on mortality among patients with endogenous CS. Research has mostly been limited to single-cohort studies. A previous systematic review/meta-analysis comprised only seven articles with 780 patients. All the studies were conducted prior to 2012, and most were limited to Cushing’s disease.
“In 2021, we lacked a detailed understanding of patient outcomes and mortality because of the rarity of Cushing’s syndrome,” Dr. Limumpornpetch noted.
The current meta-analysis included 91 articles that reported mortality among patients with endogenous CS. There was a total of 19,181 patients from 92 study cohorts, including 49 studies on CD (n = 14,971), 24 studies on adrenal CS (n = 2304), and 19 studies that included both (n = 1906).
Among 21 studies that reported standardized mortality rate (SMR) data, including 13 CD studies (n = 2160) and seven on adrenal CS (n = 1531), the overall increase in mortality compared to the background population was a significant 3.00 (range, 1.15-7.84).
This SMR was higher among patients with adrenal Cushing’s syndrome (3.3) versus Cushing’s disease (2.8) (P = .003) and among patients who had active disease (5.7) versus those whose disease was in remission (2.3) (P < .001).
The SMR was also worse among patients with Cushing’s disease with larger tumors (macroadenomas), at 7.4, than among patients with very small tumors (microadenomas), at 1.9 (P = .004).
The proportion of death was 0.05 for CS overall, with 0.04 for CD and 0.02 for adrenal adenomas.
Compared to studies published prior to the year 2000, more recent studies seem to reflect advances in treatment and care. The overall proportion of death for all CS cohorts dropped from 0.10 to 0.03 (P < .001); for all CD cohorts, it dropped from 0.14 to 0.03; and for adrenal CS cohorts, it dropped from 0.09 to 0.03 (P = .04).
Causes of death were cardiovascular diseases (29.5% of cases), cerebrovascular accident (11.5%), infection (10.5%), and malignancy (10.1%). Less common causes of death were gastrointestinal bleeding and acute pancreatitis (3.7%), active CS (3.5%), adrenal insufficiency (2.5%), suicide (2.5%), and surgery (1.6%).
Overall, in the CS groups, the proportion of deaths within 30 days of surgery dropped from 0.04 prior to 2000 to 0.01 since (P = .07). For CD, the proportion dropped from 0.02 to 0.01 (P = .25).