Use of blood-pressure-lowering medication and risk of prostate cancer in the Cancer Prevention Study II Nutrition Cohort

To examine the association between use of anti-hypertensive drugs and prostate cancer incidence among 48,389 men in the Cancer Prevention Study II Nutrition Cohort. Proportional hazards models were used to calculate rate ratios (RR) for use of Beta-Blockers (BBs), Calcium Channel Blockers (CCBs), and ACE Inhibitors (ACE) and incident prostate cancer in time-dependent analyses. During follow-up from 1997 to 2005, we identified 3,031 cases of incident prostate cancer. Anti-hypertensive use was associated with slightly decreased risk of all (RR = 0.90, 95% CI 0.83-0.98) and organ-confined low-grade prostate cancer (RR = 0.89, 95% CI 0.81-0.99), but was not statistically significantly associated with aggressive-fatal prostate cancer (RR = 0.93, 95% CI 0.79-1.10). BB and ACE inhibitor treatment was associated with an approximately 10% lower risk for all prostate cancer in models adjusted for age and race. These associations were attenuated and lost statistical significance when adjusted for history of heart disease. No trend with duration of use was detected. These results do not support the hypothesis that anti-hypertensive medication is strongly associated with risk of prostate cancer. Confounding by concurrent illness may explain inverse associations seen in other studies.