Finasteride Does Not Prevent Bladder Cancer: A Secondary Analysis of the Medical Therapy for Prostatic Symptoms Study

The study analyzed 2,700 men from the MTOPS Study to determine if finasteride, a drug used for benign prostatic hyperplasia and hair loss, could prevent bladder cancer by reducing dihydrotestosterone levels. With an incidence of bladder cancer at 0.8% (18 cases), the results showed no significant difference in cancer rates between those who took finasteride and those who did not (0.74% vs. 0.61%, P = 0.67). Additionally, no association was found between serum testosterone levels, prostate cancer diagnosis, or urinary symptoms and bladder cancer occurrence. The study concluded that finasteride does not prevent bladder cancer, but the results are limited due to missing data on risk factors like smoking status and the small number of bladder cancer cases. The document suggests that the lack of effect of finasteride on bladder cancer may be influenced by genomic differences in populations.