Increased Risk of Death in Cushing's Disease Persists After Remission

New data from an analysis of patient data over nearly 30 years suggests the increased risk of mortality associated with Cushing’s disease persists even after treatment.

A 4:1 matched analysis comparing data from 371 patients with Cushing’s disease with 1484 matched controls, indicated risk of mortality was 5-fold greater among those not in remission compared to matched controls, but even those in remission at the last follow-up were at a 50% greater risk of mortality compared to controls.

“To our knowledge, this is the first study that investigated mortality in an unselected cohort of patients treated for Cushing’s disease and followed up in comparison to mortality in matched controls. The mortality rate was more than doubled in patients with Cushing’s disease, and not being in remission was a strong predictor of premature death,” wrote investigators.

With a lack of consensus surrounding the impact of biochemical remission on life expectancy in patients with Cushing’s disease, a team of investigators from multiple institutions in Sweden designed their study with the intent of assessing this association with mortality in a time-to-event analysis of an unselected nationwide Cushing’s disease cohort. Using the Swedish Pituitary Registry, investigators identified 371 patients with Cushing’s disease for inclusion in their analysis.

The Swedish Pituitary Register is a nationwide registry that collected data on the majority of Swedish patients with Cushing’s disease. For the current study, investigators included all patients with Cushing’s disease from the register diagnosed between May 1991-September 2018 and followed these patients until the date of death, date of emigration, or December 26, 2018. From the register, investigators obtained data related to date of diagnosis, age, sex, treatment, and biochemical remission status evaluations.

The median age at diagnosis was 44 (IQR, 32-56) years and the median follow-up was 10.6 (IQR, 5.7-18) years. The remissions rates for the study cohort were 80%, 92%, 96%, 91%, and 97% at the 1-, 5-, 10-, 15- and 20-year follow-ups, respectively. These patients were matched in a 4:1 based on age, sex, and residential area at the diagnosis data, yielding a cohort of 1484 matched controls.

Upon analysis, the overall risk of mortality was greater among those with Cushing’s disease compared to the matched controls (HR, 2.1 [95% CI, 1.5-2.8]). Investigators pointed out increased risk was observed among patients in remission at the last follow-up (n=303; HR, 1.5 [95% CI, 1.02-2.2]), those in remission after a single pituitary surgery (n=177; HR, 1.7 [95% CI, 1.03-2.8]), and those not in remission (n=31; HR, 5.6 [95% CI, 2.7-11.6]). Additionally, results indicated cardiovascular disease and infections were the most overrepresented cases of death, accounting for 32 and 12 of the 66 total instances of mortality.

“The findings of the present study confirm and complement previous findings of increased overall mortality in Cushing’s disease patients, having a more than doubled HR for death compared to matched controls. Most importantly, an increased HR persisted among patients who had been successfully treated and reached a Cushing’s disease biochemical cure,” investigators added.

This study, “Increased mortality persists after treatment of Cushing’s disease: A matched nationwide cohort study,” was published in the Journal of the Endocrine Society.