Bladder Cancer Survival of Men Receiving 5α-Reductase Inhibitors.

PURPOSE: Androgens may have a role in bladder carcinogenesis. We studied whether 5α-reductase inhibitors were associated with bladder cancer specific mortality in a population based cohort of men with bladder cancer. MATERIALS AND METHODS: The study cohort consisted of 10,720 Finnish men with bladder cancer newly diagnosed in 1997 to 2012 who were identified in a national cancer registry. Median followup was 4.17 years after bladder cancer diagnosis. We analyzed the HR and 95% CI of the risk of bladder cancer death by 5α-reductase inhibitor administration using Cox regression adjusted for age, gender, comorbidities, primary bladder cancer treatment and tumor extent at diagnosis. Lag time analyses were performed to assess the long-term risk association. Simultaneous administration α-blockers was considered to estimate possible confounding by indication. RESULTS: Administering 5α-reductase inhibitors before bladder cancer diagnosis was associated with a lower risk of bladder cancer death (HR 0.84, 95% CI 0.73-0.97). The risk decrease became stronger with years of use. Conversely prediagnostic administration of α-blockers was not associated with bladder cancer survival (HR 1.02, 95% CI 0.91-1.13). Similarly 5α-reductase inhibitor administration after diagnosis was associated with a decreased risk of bladder cancer death (HR 0.77, 95% CI 0.68-0.88). Bladder cancer survival was not associated with α-blockers (HR 0.98, 95% CI 0.90-1.07). The risk decrease due to 5α-reductase inhibitors persisted up to 5 years. CONCLUSIONS: Patients who receive 5α-reductase inhibitors have improved disease specific survival after bladder cancer diagnosis compared to those who do not receive them while α-blockers were not associated with survival. This supports the benefits of 5α-reductase inhibitors in bladder cancer.