The use of five-alpha reductase inhibitors and their association with reclassification and pathologic outcomes in the Canary Prostate Active Surveillance Study (PASS).

22Background: The outcomes of patients who enroll in active surveillance (AS) programs for prostate cancer (PCa) while currently taking five-alpha reductase inhibitors (5-ARIs) have not been well defined. Previous studies suggest that the initiation of 5-ARIs after enrolling in AS decreases the rate of reclassification and/or treatment for PCa, but there is still an FDA black box warning about the risk of grade risk prostate cancer while on 5-ARI. The objective of this study was to evaluate the safety of remaining on a 5-ARI after initiating AS for PCa. Methods: All men were enrolled in PASS. Inclusion criteria were current or never 5-ARI user, Gleason 3+3 or 3+4 PCa at diagnosis, ≤ 34% core ratio at diagnosis and ≥ 1 surveillance biopsy. Reclassification was defined as an increase in Gleason score and/or ratio of biopsy cores positive for cancer to ≥ 34%. Results: 1045 men were included in this study, 938 who had never used a 5-ARI and 107 5-ARI users. 5-ARI users had larger prostate volume (51 cc vs 40 ...