Background: Androgen deprivation therapy (ADT) is used to delay tumour development and improve survival in patients with prostate cancer. However, several randomized controlled trials and observational studies have suggested that ADT may increase the risk of cardiovascular events.
Objective: The aim of the study was to evaluate the risk of coronary heart disease (CHD) and heart failure (HF) in patients with prostate cancer receiving ADT in UK primary care, and to evaluate the risks associated with individual ADT and combination ADT.
Methods: The UK General Practice Research Database was used to identify a cohort of patients with a first prostate cancer diagnosis during 1999-2005. These patients were followed up to assess the occurrence of acute myocardial infarction (AMI), death from CHD, incident HF and hospitalization due to acute decompensated HF. Nested case-control analyses were performed to assess the risk of these outcomes associated with anti-androgen therapy, as well as different types of ADT and combinations of ADT.
Results: Current anti-androgen use was associated with a significant increase in the risk of hospitalization due to HF (odds ratio [OR] 2.15; 95% CI 1.08, 4.29), but not of incident HF, CHD or AMI. When assessed individually, there was no significant association of bicalutamide or cyproterone use with the risk of AMI or CHD. Current use of bicalutamide 50 mg/day was associated with a significant increase in the risk of HF (OR 3.28; 95% CI 1.31, 8.18); however, this increased risk of HF was only found in patients taking bicalutamide 50 mg/day in combination with luteinizing hormone-releasing hormone (LHRH) receptor agonists. There were no cases of hospitalized HF in patients taking bicalutamide 50 mg/day as monotherapy and there was no significant association between current use of bicalutamide 150 mg/day and the risk of hospitalized HF. Combination therapy with LHRH agonists and anti-androgens was associated with a significant increase in the risk of CHD (OR 4.35; 95% CI 1.94, 9.75), AMI (OR 3.57; 95% CI 1.44, 8.86), incident HF (OR 3.19; 95% CI 1.10, 9.27) and hospitalized HF (OR 3.39; 95% CI 1.07, 10.70) compared with non-use of these drugs.
Conclusions: In men with prostate cancer, combination therapy with LHRH agonists and anti-androgens is associated with significant increases in the risk of CHD, AMI, incident HF and hospitalized HF. Individual therapies do not appear to increase the risk of these outcomes.