Introduction

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 cc, p < 0.01), a higher rate of BPH (77% vs 29%, p < 0.01) and older age (65 vs 62 years, p < 0.01). All other clinical parameters, including serum PSA, were statistically similar._x000D_ _x000D_ There was no significant difference in any reclassification (p = 0.12). The use of 5-ARI at diagnosis was significantly protective for reclassification in a proportional hazards model (HR 0.68, p = 0.03); this difference was not significant after accounting for serum PSA, BMI, prostate size and positive cores ratio at diagnosis (HR 0.78, p = 0.18) (Table). There was no significant effect on adjusted analysis when evaluating for disease upgrading._x000D_ _x000D_ 171 patients underwent radical prostatectomy (RP), 158 never 5-ARI users and 13 5-ARI users. There were no statistically significant differences when evaluating for Gleason grade or adverse pathology. 5-ARI users had a longer median time to RP (3.6 vs 2.1 years, p = 0.045).

Conclusions

There is no association between 5-ARI use at diagnosis and reclassification on AS for men in the Canary PASS cohort. 5-ARI users have a longer median time to RP and do not have more severe PCa at RP.

Funding

Canary Foundation, Department of Defense (PC130355), and Institute for Prostate Cancer Research