Long term antihypertensive drug use and prostate cancer risk: A 9-year population-based cohort analysis

Background: Recent findings from clinical trials have indicated inconsistent associations between angiotensin II receptor blockers and the risk of cancer incidence. Furthermore, the relationship between antihypertensive drugs and prostate cancer in hypertensive patients remains unclear. Methods: From Taiwan's national health insurance database, we identified 80,299 patients diagnosed with hypertension in 2001 and matched with 321,916 subjects without hypertension by age, income, urbanization level, and index day. A total of 684 hypertensive patients without antihypertensive drug use (drug non-user subcohort) were also matched (1:4) with 2736 patients on antihypertensive medication (drug subcohort) using the same criteria. Each subject in the two study groups was followed up for a maximum of nine years, during which death was considered a competing event when performing the stratified Fine and Gray regression hazards model for the estimation of prostate cancer risk for the cohorts. Uptake of antihypertensive prescription was considered a time-dependent variable. Results: Our findings indicate that patients with hypertension are at significantly increased risk for prostate cancer incidence when compared to their matched non-hypertensive counterparts (sHR = 6.80, 95% CI = 1.97-23.44, p = 0.0024). Among hypertensive patients, those with long term antihypertensive drug use are not at elevated risk of developing prostate cancer relative to non-users of antihypertensive drugs (1-5 year vs. non-user sHR= 0.99, 95% CI = 0.32-3.05; >5 year vs. non-user sHR= 0.88, 95% CI= 0.34-2.26). Conclusions: Hypertension is considered a risk factor for prostate cancer. However, long term uptake of antihypertensive medication in male hypertensive patients should not be a concern for the development of prostate cancer. (C) 2015 Elsevier Ireland Ltd. All rights reserved.