1. POTENTIAL FOR FAILURE OF FOCAL PROSTATE HEMI-ABLATION STRATEGIES PG O’Malley 1, B Al Hussein Al Awamlh 1, AM Sarkisian 1, DP Nguyen 1, S Jin 1, R Lee 1, DS Scherr 1, CE Barbieri 1, N Gumpeni 2, M Herman 1 1 Department of Urology and 2 Department of Radiology, Weill Cornell Medical College I NTRODUCTION AND O BJECTIVES Multiple strategies exist for focal therapy for prostate cancer (PCa). PCa however is a multifocal disease and our detection methods, i.e. biopsy and MRI, are limited. There is a potential for under treatment of significant disease with focal therapy. We sought to evaluate what the potential risk is by evaluating possible failure rates. ABSTRACT Prospectively collected database of men who underwent biopsy and subsequent prostatectomy at WCMC from January 2010 to May 2014. COHORT: Theoretical focal candidates were men with: Gleason <7 Unilateral disease on biopsy < 3 cores positive We constructed 3 cohorts: BX: Cohort based on biopsy pathology criteria MRI+: the same cohort minus those with MRI exclusion criteria (possible T3 or contralateral suspicious lesion) MRI P2+: the same cohort with blinded mpMRI read by experienced radiologist using PIRADS 2.0 criteria OUTCOMES: Rate of Gleason >8 Rate of non-organ confined disease (non-OCD) Rate of clinically significant bilateral disease, defined as Gleason >7 Putative Failure Rate (PFR): Presence of any of the above three criteria in the 3 cohorts: BX, MRI+, & MRI P2+ MRI Suitable = Failures/Candidates after exclusion MRI = Failures/Total Candidates before exclusion Rates were compared using chi 2 test. RESULTS METHODS Table 1. Cohort TRUS biopsy and Prostatectomy Pathology RESULTS Table 3: Putative Failure Rates for Cohorts: MRI Suitable- and MRI-PFR CONCLUSIONS The multifocal nature of PCa leads to a significant risk of failure after focal therapy. MRI imaging lowers this failure rate. However, the rate of failure, was still high at 41.7%. (MRI+ MRI-PFR) Adoption of the more rigorous PIRADS 2.0 grading system improves the ability to exclude men destined for failure decreasing the absolute rate to 30.2% (MRI P2+ MRI-PFR) However, amongst men who would have been candidates for therapy even with the most stringent criteria the relative rate of failure would still be exceedingly high (65%). (MRI P2+ MRI Suitable-PFR) This highlights the need for better risk assessment of men prior to focal therapy perhaps with MRI targeted/informed biopsy needed This requires further evaluation in a larger series of patients but may seriously call into question the oncological safety of focal therapy DATABASEBXMRI+MRI P2+ Number of Patients20061 EXCLUSION CRITERIA: Biopsy: BILATERAL/GLEASON>7 BIOPSY >3 cores No MRI MRI Exclusion: Bilateral EPE Total TOTAL EXCLUDED: 121 18 -- -- -- 13 16 5 17 -- 18 22 6 23 139 --3041 FOCAL CANDIDATES: 61 31 [of 48]20 [of 43] TRUS PATHOLOGYPROSTATECTOMY PATHOLOGY Overall Gleason Grade : Gleason 6 Gleason 7 Gleason 8/9 33 (54.1%) 28 (45.9%) -- 17 (27.9%) 43 (70.5%) 1 (1.6%) 6 (19.4%) 24 (77.4%) 1 (3.2%) 6 (30.0%) 13 (65%) 1 (5%) Predominant Lesion: Left Right 39 (63.9%) 22 (36.1%) 38/39 (97.4%) 21/22 (95.5%) 21/21 (100%) 9/10 (90%) 16/16 (100%) 3/4 (75%) Bilateral Disease: Overall Clinically significant (Gleason >7) -- 52 (85.2%) 36 (59.0%) 27 (87.1%) 20 (64.5%) 18 (90.0%) 13 (65.0%) T Stage: T2a/b T2c T3 61 (100%) -- 8 (13.1%) 41 (67%) 12 (19.7%) 4 (12.9%) 19 (61.3%) 8 (25.8%) 3 (14.2%) 12(57.1%) 5 (23.8%) COHORTFAILURES Putative Failure Rate (PFR) N= MRI suitable (%) P-valueN=MRI (%)P-value BX376160.7--6160.7-- MRI+203164.50.7294841.70.049 MRI P2+132065.00.9724330.20.002 COHORT CAUSE OF FAILURE GLEASON >8NON-OCD†BILATERAL†TOTAL BX112 (13)24 (36)37 MRI+17 (8)12 (18)20 MRI P2+14 (5)8 (13)‡13 Table 2: Putative Failures by Cohort and Cause †Unique (Total) ‡ 5 (6) of which are Gleason 7 (4+3) or greater Dr. P O’Malley supported by The Frederick J. and Theresa Dow Wallace Fund of the New York Community Trust and by the Ferdinand C. Valentine Fellowship Award from the New York Academy of Medicine.