Androgen Deprivation Therapy for Prostate Cancer Is Associated with Cardiovascular Morbidity and Mortality: A Meta-Analysis of Population-Based Observational Studies

BACKGROUND There is no consensus regarding whether androgen deprivation therapy (ADT) is associated with cardiovascular disease (CVD) and cardiovascular mortality (CVM). The objective of this study was to determine the role of ADT for prostate cancer (PCa) in development of cardiovascular events (CVD and CVM). METHODS AND FINDINGS We performed a meta-analysis from population-based observational studies comparing ADT vs control aimed at treating PCa in patients with PCa, reporting either CVD or CVM as outcome. Publications were searched using Medline, Embase, Cochrane Library Central Register of observational studies database up to May 31th 2014, and supplementary searches in publications from potentially relevant journals. 6 studies were identified with a total of 129,802 ADT users and 165,605 controls investigating the relationship between ADT and CVD. The incidence of CVD was 10% higher in ADT groups, although no significant association was observed (HR = 1.10, 95%CIs: 1.00-1.21; P = 0.06). For different types of ADT, CVD was related with gonadotropin-releasing hormone (GnRH) (HR = 1.19, 95%CIs: 1.04-1.36; P<0.001) and GnRH plus oral antiandrogen (AA) (HR = 1.46, 95%CIs: 1.03-2.08; P = 0.04), but not with AA alone or orchiectomy. For CVM, 119,625 ADT users and 150,974 controls from 6 eligible studies were included, pooled results suggested that ADT was associated with CVM (HR = 1.17, 95%CIs: 1.04-1.32; P = 0.01). Significantly increased CVM was also detected in GnRH and GnRH plus AA groups. When patients received other treatments (e.g. prostatectomy and radiotherapy) were ruled out of consideration, more increased CVD (HR = 1.19, 95%CIs: 1.08-1.30; P<0.001) and CVM (HR = 1.30, 95%CIs: 1.13-1.50; P<0.001) were found in men treated with ADT monotherapy. CONCLUSIONS ADT is associated with both CVD and CVM. Particularly, GnRH alone and GnRH plus AA can significantly increase the incidence of cardiovascular events in patients with PCa.