PD34-05 5-ALPHA REDUCTASE INHIBITORS IN PATIENTS ON ACTIVE SURVEILLANCE FOR PROSTATE CANCER: IMPACT ON DISEASE PROGRESSION AND CURATIVE INTERVENTION

INTRODUCTION AND OBJECTIVES: To report pathologic progression (PP) and curative intervention (CI) in 361 men on active surveillance (AS) in comparison between with and without use of 5alpha reductase inhibitors (5-ARI). METHODS: Total 361 patients were grouped: with use of 5-ARI (n1⁄4 119, 33%) or without use of 5-ARI (No 5-ARI), n1⁄4242 (67%). All the patients had at least two years of follow up and the median follow up time was 5.1 years for 5-ARI vs 5.3 years for No 5-ARI (p1⁄40.6). The AS protocol included PSA (6 monthly), multi-parametric transrectal ultrasound (TRUS) annually, and surveillance biopsy (2-3 yearly, or as indicated). PP was defined as upgrade on Gleason score, increase in cancer core length (>4mm) or percent (>25%), or clinical progression on the follow up. CI was defined as discontinuing AS to undergo any kind of curative or hormonal therapy. Clinical variables were compared between the two groups. Kaplan-Meier method was conducted to estimate survivals for PP and CI, and multivariable Cox regression for predictors of PP. RESULTS: At the entry, the two groups were similar: age (63 vs. 61yrs, p1⁄40.1), PSA (4.8 vs. 4.8ng/ml, p1⁄40.5), prostate volume on TRUS (41cc vs. 35cc, p1⁄40.1), clinical stage T1c/T2a (85%/13% vs. 90%/9%, p1⁄40.06), biopsy Gleason score (6/3þ4/4þ3 1⁄4 88%/10%/2% vs. 87%/11%/2%, p1⁄40.9), biopsy cancer core length (1.5mm vs. 1mm, p1⁄40.37) and percent (10% vs. 8.5%, p1⁄40.2) of index cancer, and number of positive cores (1 vs. 1, p1⁄40.1), respectively for 5-ARI vs No 5-ARI groups. Predictors of PP were: not taking 5-ARI (p1⁄40.017), entry PSA > 4ng/ml (p1⁄40.009) and Gleason pattern 4 in biopsy (p<0.001). In regression analyses, 5-ARI-group had lowered the risk of PP by 41%. Estimated probability of PP-free survival (Fig 1) and CI-free survival (Fig 2) are shown: CONCLUSIONS: The use of 5-ARI for selected patients on AS delayed PCa progression and curative intervention. Source of Funding: None