In the Fall of 2010, the FDA called for new labeling for gonadotropin-releasing hormone (GnRH) agonists used for ADT to warn of possible adverse outcomes in men with prostate cancer. The warning was supported by evidence largely from observational studies linking GnRH agonists to increased risks of cardiovascular death and diabetes (Cancer 2009 Jun 1;115(11):2388, J Natl Cancer Inst 2010 Jan 6;102(1):39). Now, a new systematic review of 11 unblinded randomized trials suggests that GnRH agonist-based ADT may not increase cardiovascular mortality in this population (level 2 [mid-level] evidence).
In each trial, men with unfavorable-risk, nonmetastatic prostate cancer were randomized to ADT vs. no immediate ADT and were followed for 7.6-13.2 years. In a meta-analysis of 8 trials with 4,141 men, there was no significant difference in cardiovascular mortality between groups (relative risk 0.93, 95% CI 0.79-1.1). There were also no significant differences in analyses of trials stratified by treatment duration (5 trials ≥ 3 years, 3 trials ≤ 6 months). However, ADT significantly reduced both all-cause mortality and prostate cancer-specific mortality in analysis of all 11 trials (JAMA 2011 Dec 7;306(21):2359).
For more information, see the Androgen deprivation therapy for prostate cancer topic in DynaMed.