1092 5-alpha reductase inhibitors diminish the rate of progression in men with low risk prostate cancer on active surveillance

Abstract

INTRODUCTION AND OBJECTIVES: 5-alpha reductase inhibitors (5ARIs) have been shown to prevent prostate cancer in two large randomized controlled trials. No prior work has shown the effect of 5ARIs on those already diagnosed with low risk prostate cancer. Our goal was to determine the effect of 5ARIs on pathologic progression in men on active surveillance for prostate cancer. METHODS: This was a single institution retrospective cohort study comparing men taking a 5ARI versus no 5ARI while on active surveillance for prostate cancer. All men had at least two biopsies. Inclusion criteria for active surveillance were PSA 10 ng/ml, clinical stage T1c/T2a, Gleason score 6, and 3 cores positive with no more than 50% of a core involved at initial diagnostic biopsy. Pathologic progression was evaluated and defined as Gleason score 6, or maximum core involvement 50% or 3 cores positive on a follow-up prostate biopsy. Univariate, multivariate and Kaplan-Meir analyses were conducted. RESULTS: A total of 288 men on active surveillance met the inclusion criteria. The median follow-up was 38.5 months (IQR 23.6– 59.4) with 93 men (32%) experiencing pathologic progression and 96 men (33%) abandoning active surveillance. Men taking a 5ARI experienced a lower rate of pathologic progression (18.6% vs 36.7%, p 0.004) and were less likely to abandon active surveillance (20% vs 37.6%, p 0.006). The median time to progression was longer in the 5ARI group (42.5 months) compared to the non-5ARI group (31.5 months; p 0.026). On multivariate analysis, lack of 5ARI use was most strongly associated with pathologic progression (OR 2.98, 95% CI 1.5–5.9) followed by age and baseline maximum percentage involvement of any biopsy core. CONCLUSIONS: 5ARIs were associated with a significantly lower rate of pathologic progression and abandonment of active surveillance.