Men with continuous use of 5-alpha reductase inhibitors (5-ARIs) may have a lower bladder cancer risk, according to a poster presentation at the 2022 American Urological Association’s annual meeting in New Orleans, Louisiana.

As previous studies on the topic have yielded conflicting results, Snir Dekalo, MD, of Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel, and colleagues conducted a retrospective study of 93,197 men from Ontario, Canada, who initiated either dutasteride (52%) or finasteride (48%) and matched them with the same number of men who did not start a 5-ARI.

The risks for bladder cancer diagnosis and mortality were a significant 24% and 34% lower, respectively, among users than nonusers over a median at-risk period of 1.68 years, Dr Dekalo reported. After adjustments for variables related to prior bladder cancer investigations, the risk reduction in bladder cancer mortality was no longer significant, whereas continuous use of 5-ARIs for at least 2 years was significantly associated with an 18% lower risk of a bladder cancer diagnosis.

Continue Reading

“Among studies that sought to determine whether 5-ARIs have a role in bladder cancer prevention, some demonstrated positive correlation and some negative,” co-investigator Blayne Welk, MD, MSc, of Western University, London, Ontario, Canada, noted in an interview. “Our study examined compliance to treatment and is an important milestone in this field. Further research is needed to better understand the findings.”

The Prostate Cancer Prevention Trial, a randomized controlled study, aimed to determine if 5-ARIs prevent prostate cancer. The same design will be best to evaluate whether 5-ARIs prevent bladder cancer, Dr Welk said.


Dekalo S, McArthur E, Campbell J, et al. 5 alpha-reductase inhibitors and the risk of bladder cancer in a large, population-based cohort. Presented at: AUA 2022; May 13-16, 2022, New Orleans, Louisiana. Abstract MP42-03.