You have accessJournal of UrologyCME1 May 2022MP42-03 5α-REDUCTASE INHIBITORS AND THE RISK OF BLADDER CANCER IN A LARGE, POPULATION-BASED COHORT Snir Dekalo, Eric McArthur, Jeff Campbell, Michael Ordon, Nicholas Power, and Blayne Welk Snir DekaloSnir Dekalo More articles by this author , Eric McArthurEric McArthur More articles by this author , Jeff CampbellJeff Campbell More articles by this author , Michael OrdonMichael Ordon More articles by this author , Nicholas PowerNicholas Power More articles by this author , and Blayne WelkBlayne Welk More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002608.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The ability of 5α-Reductase Inhibitors (5ARI) to reduce the risk of new onset bladder cancer (BC) has been studied with variable results. As such, our aim was to conduct a retrospective cohort population-based study to evaluate the association between 5ARI use, BC diagnosis, and BC mortality. METHODS: We used routinely collected health care data from Ontario, Canada. Men ≥66 years of age with a prescription for a 5ARI were matched to non-5ARI users. Matching was done using a propensity score of selected covariates to make 96 different covariates comparable. We also measured an additional five baseline variables which may have impacted the risk of future BC diagnosis: cystoscopy, cytology, Urine-dip, hematuria, and transurethral resection of bladder lesion. Only the first period of continuous use of 5ARIs was considered. The prespecified at-risk period for outcomes started 1 year after initiating therapy (this lag period allowed time for a biologically plausible effect from the 5ARI to occur) and ended at the last date of 5ARI exposure + 1 year (to allow time for BC to be diagnosed, and due to the residual effects of 5ARIs). RESULTS: We identified 93,197 men who initiated 5ARI therapy (52% dutasteride, and 48% finasteride). between 2003-2013 and matched them 1:1 to men who did not start a 5ARI. The median at-risk period for the 5ARI group was 1.68 years (IQR 1.00, 4.27). Both BC diagnosis and BC mortality were significantly less common during the at-risk period among the 5ARI group (HR 0.76, 95%CI 0.70-0.83; and HR 0.66, 95%CI 0.53-0.82 respectively). With adjustment for the variables related to prior BC investigations there was no significant difference in BC diagnosis (HR 1.05 95%CI 0.82-1.32 during the period of 0-<2 years of 5ARI use; however after ≥2 years of 5ARI use the risk of BC diagnosis was significantly less among the 5ARI group (HR 0.82, 95%CI 0.79-0.94). In the adjusted model, BC mortality was lower among 5ARI users, but no longer significant (HR 0.82, 95%CI 0.65, 1.02). CONCLUSIONS: In a large cohort of men using 5ARI, we demonstrated a decreased risk of BC diagnosis. This risk reduction was present after ≥2 years of continuous therapy. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e730 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Snir Dekalo More articles by this author Eric McArthur More articles by this author Jeff Campbell More articles by this author Michael Ordon More articles by this author Nicholas Power More articles by this author Blayne Welk More articles by this author Expand All Advertisement PDF DownloadLoading ...