with detailed and validated clinicopathologic data for all patients with newly-diagnosed CaP. For this analysis, we identified all men who un- derwent RP for clinically low-risk CaP (defined as clinical stage T1 or T2a, prostate specific antigen (PSA) <10 ng/mL, and biopsy Gleason score 6) from 1/2011 through 8/2015. We compared differences in the fre- quency of adverse pathologic outcomes (e.g., Gleason score upgrading, seminal vesicle involvement, positive surgical margins) among patients selecting initial RP versus initial AS with subsequent transition to RP. RESULTS: During this interval, 2,858 patients with low-risk CaP were entered into the MUSIC registry. Among this group, 778 (27%) and 1,359 (48%) patients selected initial RP and initial AS, respectively. AS patients were older (63.4 vs. 60.1 years, p<0.001) with similar PSA levels (5.4 vs. 5.0 ng/mL, p¼0.08 for initial AS and RP groups, respectively), but less likely to have clinical T2a disease (5.1% vs 14.5%, p¼0.02). Among the AS cohort, the median follow-up was 506 days (IQR 280-793 days), and 79 (5.8%) transitioned to RP. Men managed with initial AS were more likely to have a pathological Gleason Score  7; however there were no other differences between these groups with respect to adverse pathology outcomes (Table 1). CONCLUSIONS: Patients with low risk CaP that enter AS have higher grade disease at RP compared to those undergoing initial RP. The lack of differences in other pathologic outcomes suggests that the surveillance process may be appropriately identifying patients with more aggressive cancers prior to stage progression. Source of Funding: Blue Cross and Blue Shield of Michigan and grant 1T32-CA180984 from the National Cancer Institute. PD03-04 LONG-TERM ONCOLOGIC OUTCOMES OF RADICAL PROSTATECTOMY IN A LARGE COHORT OF PATIENTS ON ACTIVE SURVEILLANCE Ardalan E. Ahmad*, Maria Komisarenko, Ruby Grewal, Narhari Timilshina, Robert Hamilton, Girish Kulkarni, Alexandre Zlotta, Neil Fleshner, Antonio Finelli, Toronto, Canada INTRODUCTION AND OBJECTIVES: Active Surveillance (AS) is widely accepted as the treatment of choice for favorable risk Prostate Cancer (PCa). With the increasing number of men enrolling in AS it is important to understand the treatment outcomes in men who progress on AS and require definitive therapy in the form of radical prostatectomy (RP). We sought to examine the impact of delayed definitive treatment on oncologic outcomes in a cohort of men progressing on active sur- veillance to RP with a long-term follow up. METHODS: We retrospectively reviewed a prospectively maintained database of men on AS from 01/1998-06/2014 at Princess Margaret Cancer Centre (PM). We identified patients on AS who un- derwent RP as definitive treatment. Biochemical recurrence (BCR) rate was compared to age and prostate specific antigen matched men un- dergoing immediate radical prostatectomy after a diagnosis of low risk disease who were candidates for active surveillance (control). RESULTS: 1246 men met the PM’s AS criteria at diagnosis, 250 patients (20%) progressed on AS to RP. The control group consist of 138 patients. There was no age difference between the 2 groups (P>0.05). At median follow up of 5.7 years (IQR 0.2 to 15.9), 16.7% of patients compared to 5.4% of controls experienced BCR (p¼0.005). Delayed RP was associated with a significantly shorter time to BCR compared to control group (median 3 years (0.3-15.1) vs. median 4.7 years, (0.2-13.0)). Clinical stage (T stage) at diagnosis was the only factor predictive of BCR on multivariate analysis. CONCLUSIONS: In a non-pathologically matched cohort of patients on AS, patients who progressed to RP had a significantly higher BCR rate compared to patients who underwent immediate RP after diagnosis. While these findings are concerning, comparison of pathological outcomes, cancer specific survival and overall survival between the 2 groups will help us a better understanding the implication of higher BCR rate in delayed RP group. Source of Funding: None PD03-05 UPSTAGING IN RADICAL PROSTATECTOMY IN THE POST-PSA ERA: AN EFFECT OF DELAYED DIAGNOSIS OR BETTER PATIENT SELECTION? Katherine Rotker*, Joseph Brito, Liz Edmund, Andres Matoso, Joseph Renzulli, Providence, RI INTRODUCTION AND OBJECTIVES: Serum prostate-specific antigen (PSA) levels had been widely used for screening of prostate cancer until May of 2012 when the U.S. Preventive Services Task Force (USPSTF) recommended against it based on concern for harm due to screening and over treatment of clinically insignificant prostate cancer. We aimed to study changes in radical prostatectomy findings after the issue of USPSTF recommendation against PSA screening. METHODS: We retrieved and reviewed all consecutive RP performed at our institution immediately after the USPSTF issued its recommendation against PSA-based screening for prostate adenocar- cinoma (5/2012) until 5/2015 (3 years). The control group included all RPs in the 3 years immediately before the USPSTF recommendation. RESULTS: After 2012, the proportion of Gleason score 6 can- cer decreased from 24.35% to 12.22% (p¼<0.01), the proportion of Gleason score 4+3¼7 increased from 12.45% to 20.58% (p¼0.01) and the proportion of Gleason score 8 or above increased from 8.4% to 13.18% (p¼0.04). Over this same time period, the proportion of RP with organ confined disease decreased from 71.43% to 62.7% (p¼0.01), the proportion of T3 disease increased from 29.2% to 38.26% (p¼0.01) and Vol. 195, No. 4S, Supplement, Friday, May 6, 2016 THE JOURNAL OF UROLOGY â e57