The Association Between Statin Use and Outcomes in Patients Initiating Androgen Deprivation Therapy

Abstract

BackgroundStudies have conflicting results regarding the association between statin use and biochemical recurrence for prostate cancer (PCa). A limited number of studies examining statins in advanced stages report positive results, with a few specifically examining statins and androgen deprivation therapy (ADT). ObjectiveTo perform a post hoc secondary analysis of a randomised controlled trial (RCT) of men initiating ADT to examine the association between statin use and outcomes. Design, setting, and participantsPatients with prostate-specific antigen (PSA) >3 ng/ml >1 yr following primary/salvage radiotherapy were enrolled in an RCT of intermittent androgen deprivation (IAD) versus continuous ADT (NCT00003653). Baseline and on-study statin use was modelled as a time-dependent covariate. Outcome measurements and statistical analysisThe primary endpoint was overall survival. Models were adjusted for age, time from radiotherapy to ADT, baseline PSA, and prior ADT. Results and limitationsOf 1364 patients, statin users (585; 43%) were younger (72.7 vs 73.8 yr, p = 0.001) and less likely to have PSA >15 ng/ml (20% vs 25%, p = 0.04). After a median follow-up of 6.9 yr, statin use was associated with reduced overall (hazard ratio [HR]: 0.64; 95% confidence interval [CI] 0.53–0.78, p < 0.001) and PCa-specific (HR: 0.65, 95% CI 0.48–0.87, p = 0.004) mortality. Statin users had 13% longer time to castration resistance, but this did not reach statistical significance (p = 0.15). As an exploratory endpoint, in the IAD arm, statin users had longer time off treatment (median: 0.85 vs 0.64 yr, p = 0.06). Limitations include potential for residual confounding between statin users and nonusers, and confounding by indication. ConclusionsIn men treated with ADT following primary or salvage radiotherapy, statin use was associated with improved overall and PCa-specific survival. In patients treated with IAD, statin use was associated with a trend towards longer time off treatment. A prospective trial of statins in men commencing ADT is warranted. Patient summaryWe found a favourable association between statin use and survival outcomes in patients initiating androgen deprivation therapy.