5α-Reductase Inhibitor Use and Progression of Bladder Cancer in South Korean Males

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In a Korean cohort study reported in JAMA Network Open, An et al found that men with prescriptions for 5α-reductase inhibitors prior to diagnosis of urothelial bladder cancer had better outcomes than those with no prior prescriptions.

Study Details

The study analyzed patient claims data from the Korean National Health Insurance Service database, with the study cohort including all male patients with a bladder cancer diagnosis from January 2008 to December 2019. Propensity-score matching was performed to derive two treatment groups: those who received α-blockers only (n = 5,300) and those who received 5α-reductase inhibitors and α-blockers (n = 5,300). Those in the 5α-reductase inhibitor group had to have newly dispensed prescriptions of 5α-reductase inhibitors at least 12 months prior to cancer diagnosis and a minimum of two prescriptions filled. The primary outcome measures were risks of bladder instillation and radical cystectomy.

Key Findings

Compared with the α-blocker group, the 5α-reductase inhibitor plus α-blocker group had lower risks of bladder instillation (adjusted hazard ratio [aHR] = 0.84, 95% confidence interval [CI] = 0.77–0.92), radical cystectomy (aHR = 0.74, 95% CI = 0.62–0.88), and all-cause mortality (aHR = 0.83, 95% CI = 0.75–0.91).

Restricted mean survival times were significantly longer in the 5α-reductase inhibitor plus α-blocker group for bladder instillation (difference = 88.1 days, 95% CI = 25.2–150.9 days), radical cystectomy (difference = 68.0 days, 95% CI = 31.6–104.3 days), and all-cause mortality (difference = 92.6 days, 95% CI = 25.7–159.4 days).

The incidence rates per 1,000 person-years for the 5α-reductase inhibitor plus α-blocker group vs α-blocker group were 66.43 (95% CI = 62.22–70.84) vs 85.59 (95% CI = 80.53–90.88) for bladder instillation and 13.56 (95% CI = 11.86–15.45) vs 19.57 (95% CI = 17.41–21.91) for radical cystectomy.

The investigators concluded, “Results of this study suggest an association between prediagnostic prescription of 5α-reductase inhibitors and reduced risk of bladder cancer progression.”

Seok Ho Kang, MD, PhD, of the Department of Urology, Anam Hospital, Korea University College of Medicine, Seoul, and Rae Woong Park, MD, PhD, of the Department of Biomedical Informatics, Ajou University School of Medicine, Suwon, are the corresponding authors for the JAMA Network Open article.

Disclosure: The study was funded by the Korean Urological Association, Korea Health Industry Development Institute, and others. For full disclosures of the study authors, visit

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