Quantifying observational evidence for risk of fatal and nonfatal cardiovascular disease following androgen deprivation therapy for prostate cancer: a meta-analysis

Abstract

Context: Whether androgen deprivation therapy (ADT) for men with prostate cancer (PCa) increases the risk of cardiovascular disease (CVD) remains controversial. Pooled analyses using data from randomised controlled trials suggest no increased risk of fatal CVD following ADT, but no pooled analyses exist for observational studies.

Objective: To perform a meta-analysis using observational data on ADT and risk of CVD events in men with PCa.

Evidence acquisition: PubMed and Embase were searched using predefined inclusion criteria to perform meta-analyses on associations between types of ADT and nonfatal and fatal CVD outcomes using information from observational studies. Random effects meta-analyses were conducted to estimate relative risks (RRs) and 95% confidence intervals (CIs).

Evidence synthesis: A total of eight observational studies were identified studying at least one type of ADT and a nonfatal or fatal CVD outcome. The RR for risk of any type of nonfatal CVD was 1.38 (95% CI, 1.29-1.48) for men with PCa on gonadotropin-releasing hormone (GnRH) agonists, compared with men not treated with ADT. When analysing nonfatal ischemic heart disease only, the RR was 1.39 (95% CI, 1.26-1.54). The associations between GnRH agonists and nonfatal or fatal myocardial infarction or stroke were even stronger: RR: 1.57 (95% CI, 1.26-1.94) and RR: 1.51 (95% CI, 1.24-1.84), respectively. The results for other types of ADT in relation to the risk of any nonfatal CVD were RR: 1.44 (95% CI, 1.28-1.62) for orchiectomy and RR: 1.21 (95% CI, 1.07-1.367) for antiandrogens.

Conclusions: Observational data show a consistent positive association between ADT and the risk of CVD. This finding supports the need for future randomised trials of PCa patients that include older patients and men with multiple comorbidities to better reflect the general population.

Patient summary: We investigated all the available data from observational studies on hormonal treatment for prostate cancer and its possible cardiovascular adverse effects. We found consistent evidence that this treatment may increase the risk of cardiovascular disease.

Keywords: Androgen deprivation therapy; Cardiovascular disease; Morbidity; Mortality; Prostate cancer.