Patients with Cushing’s disease who have been in remission for more than 10 years still have an increased mortality risk compared with the general population, says an international team of researchers, who found the risk of early death was particularly increased in those with Cushing’s and accompanying circulatory disease.
Richard N Clayton, MD, department of medicine, Keele University, Stoke-on-Trent, United Kingdom, showed that Cushing’s disease, which is characterized by increased secretion of adrenocorticotropic hormone by the anterior pituitary gland, is associated with an increased mortality risk of more than 60% and a median survival of around 40 years.
In patients who also had circulatory disease, the mortality risk was even higher, say Dr Clayton and colleagues.
However, patients who had undergone curative pituitary surgery had a long-term risk of death no different from that of the general population. US Endocrine Society guidelinespublished last August recommend that optimal treatment of Cushing’s syndrome involves direct surgical removal of the causal tumor.
But Dr Clayton and colleagues point out that even patients who undergo pituitary surgery will nevertheless “require lifelong follow-up at a center experienced in dealing with this condition, having regular checks for diabetes, hypertension, and other cardiovascular risk factors.”
The study was published online June 2 in Lancet Diabetes & Endocrinology.
In an accompanying editorial, Rosario Pivonello, MD, PhD, department of clinical medicine and surgery, section of endocrinology, University of Naples Federico II, Italy, and colleagues write that, although surgery is not suitable for all patients, “Prompt pituitary surgery might be the preferred treatment for Cushing’s disease to guarantee the best mortality outcome.”
Calling for further research to better understand why one treatment “has a better effect on mortality than another,” they state: “The results from this study might also motivate rapid interventions, cure, and long-term follow-up in patients with Cushing’s disease — even for a long time after hypercortisolism resolution.”
Studying Those Who Have Survived More Than 10 Years
Dr Clayton and colleagues explain that previous studies have explored mortality in patients with Cushing’s disease during either active disease or remission. But the outcome of patients in remission, especially long-term remission, is still a matter of debate, and assessing long-term survival has been limited by various methodological differences. To overcome some of these issues, they performed a retrospective analysis of case records from specialist referral centers in the United Kingdom, Denmark, the Netherlands, and New Zealand.
They identified 320 patients diagnosed with Cushing’s disease and cured for a minimum of 10 years at enrollment and had no relapses during the study period. The ratio of women to men was 3:1.
Median patient follow-up was 11.8 years, yielding a total of 3790 person-years of follow-up 10 years after cure. There was no difference in follow-up between countries. And as there were no significant demographic and clinical differences between men and women, the data were pooled.
During the study 16% of patients died. Median survival was 31 years for women and 28 years for men, at approximately 40 years following remission. The overall standardized mortality ratio (SMR) for all-cause mortality compared with the general population was 1.61 (P = .0001).
Patients with Cushing’s and circulatory disease had an SMR vs the general population of 2.72 (P < .0001), but deaths from cancer among those who had survived Cushing’s disease were not higher than the general population, at an SMR of 0.79 (P = .41).
Patients with Cushing’s and diabetes also had an increased mortality risk, at a hazard ratio (HR) of 2.82 (P < .0096) compared with the general population, while hypertension was not significantly associated with increased mortality, at an HR of 1.59 (P = .08).
There was also an association between mortality and number of treatments, at an HR of 1.77 for two vs one treatment (P = .08) and an HR of 2.6 for three vs one treatment (P = .02).
Pituitary Surgery Alone Associated With No Increased Risk of Death
Pituitary surgery performed as the first and only treatment was associated with an SMR vs the general population of 0.94 compared with an SMR of 2.58 for other patients (P < .0005).
Patients who had pituitary surgery only had a median survival of 31 years compared with 24 years if surgery had been required at any time (P = 0.03).
The research team states: “For patients who have been cured of Cushing’s disease for 10 years or more, treatment complexity and an increased number of treatments, reflecting disease that is more difficult to control, appears to negatively affect survival.”
“Pituitary surgery alone achieves a mortality outcome that is not different from the normal population and should be performed in a center of excellence,” they conclude.
However, in the editorial, Dr Pivonello and colleagues point out that the surgical approach “is not a treatment option for some patients, either because of contraindications (eg, severe clinical complications) or because of an absence of clear indication for surgery (eg, tumor is not completely removable by surgery).”