New perioperative risk factors for biochemical recurrence after robotic assisted radical prostatectomy: A single surgeon experience in high volume Canadian center Emad Rajih1,2, Malek Meskawi1, Abdullah M. Alenizi1, Kevin C. Zorn1, Assaad El-Hakim1 1Division of Robotic Urology, Hôpital du Sacré Cœur de Montréal, University of Montreal, Montreal, Quebec, Canada. 2Urology department, Taibah University, Madinah, Saudi Arabia All authors confirm no conflicts of interest RESULTS INTRODUCTION Covariates No BCR n=273 +ve BCR n=53 p-value Multivariate analysis RR (CI 95%; p-value) Mean (median) or number of patients (%) Age (year) 60.8 (61) 60.1 (61) 0.65 - BMI 28 (26.8) 28.1 (26.2) 0.97 Prostate size 49.5 (47) 48 (44) 0.17 PSA (ng/ml) 6.54 (5.5) 8.9 (6.9) 0.003 1.16 (9.9-1.4); 0.17 PSAD 0.14 (0.11) 0.2 (0.14) 0.006 0.008(0-19.1); 0.17 Grade 6 3+4 4+3  8   46 (90.2%) 183 (89.7%) 17 (60.7%) 27 (62.8%) 5 (9.8%) 21 (10.3%) 11 (39.3%) 16 (37.2%) 0.0001 Reference 0.5 (0.16-1.8); 0.30 3.1 (0.72-13.48); 0.12 1.76 (0.35-8.71); 0.49 Pathological stage T2a-b T2c T3a T3b-T4 65 (89%) 151 (88.3%) 48 (76.2%) 9 (47.4%) 8 (11%) 20 (11.7%) 15 (23.8%) 10 (52.6%) 0.7(0.25-2.34); 0.64 1.59 (0.44-5.67); 0.48 1.15 (0.2-6.49); 0.87 Prop Positive cores 3.9 (4) 4.4 (4) 0.96(0.69-1.06); 0.78 Surgical margin -ve SM +ve SM 222 (90.2%) 51 (63.7%) 24 (9.8%) 29 (36.3%) 5.1 (2.1-12.5); 0.0001 % Biopsy tumor volume 34.3 (33.3) 40.1 (41.6) 0.06 1.01(0.98-1.06);0.38 Statin use No Yes 180 (90.2%) 93 (84.5%) 36 (16.7%) 17 (15.5%) 0.77   Covariates No BCR n=273 +ve BCR n=53 p-value Multivariate analysis RR (CI 95%; p-value) Mean (median) or number of patients (%) Year of Surgery 2006 – 2010 2011 – 2015 118 (78.1%) 155 (88.6%) 33 (21,9%) 20 (11.4%) 0.01 1 (1.0-1.0); 0.01 Operative time (min) 208.2 (200) 249 (226) 0.0001 1 (1-1.02); 0.04 Blood loss (ml) 326 (300) 340 (300) 0.61 0.9 (0.98-1.0); 0.29 NVB release time (min) 43 (41) 52 (50) 0.001 - Apical resection time (min) 10 (0.11) 14 (0.14) 0.006 0.9 (0.94-1.04); 0.71 NVB preservation No Unilateral Bilateral 49 (80.3%) 95 (84.1%) 129 (84.9%) 12 (19.7%) 18 (15.9%) 23 (15.1%) 0.77 Reference 0.96 (0.3-3.09); 0.95 1.15(0.35-3.76); 0.81 Compromised pelvis Yes 219 (85.2%) 54 (78.3%) 38 (14.8%) 15 (21.7%) 0.16 Capulotomy 202 (84.2%) 71 (82.6%) 38 (15.8%) 15 (21.4%) 0.72 Overall difficulty Easy Mixed difficult 115 (87.1%) 71 (80.7%) 87 (82.1%) 17 (12.9%) 17 (19.3%) 19 (17.9% 0.38 Biochemical recurrence (BCR) is observed in up to 35% of patients following radical prostatectomy.1 These patients will require further treatments. Hence, it is essential to predict recurrence for accurate prognostication and for treatment purposes. OBJECTIVE To identify and assess new predictive factors for BCR in patients undergoing robotic assisted radical prostatectomy (RARP) in a Canadian cohort. METHODOLOGY Data was collected prospectively on 326 patients. All patients were operated by a single surgeon (AEH) between 2006-2015. Minimum follow up was 2 years. None of the patients had neo-adjuvant therapy. Variables analyzed included age, body mass index (BMI), year of surgery, statin use, oncological parameters, prostate volume, operative time, estimated blood loss, number of neurovascular bundles (NVB) preservation, NVB preservation time, apical dissection time, presence of capsulotomy, and difficult pelvis anatomy (narrow and deep). BCR was defined as PSA >0.2 ng/ml, or patients who received adjuvant or salvage radiotherapy, and/or hormonal deprivation therapy. Univariate and multivariate logistic regression analysis were performed to identify perioperative factors associated independently with BCR. [Tables 1 and 2] Kaplan Meier curves and Log Rank test were used to assess the risk of BCR in negative versus positive SM groups. [ Fig. 1] Table 1. Baseline characteristics. Table 2. Perioperative predictive factors. Figure 2. Positive surgical margin locations and risk of BCR. Figure 1. Kaplan Meier shows the comparison of risk of BCR in SM groups. (0= -ve SM; 1= +ve SM) STUDY LIMITATIONS REFERENCES RESULTS Retrospective study Shorter follow up period compared to the literatures Limited number of patients 1- Han M, Partin AW, Pound CR, et al. Long-term biochemical disease-free and cancer-specific survival following anatomic radical retropubic prostatectomy: the 15-year Johns Hopkins experience. Urol Clin North Am 2001; 28:555-65. 53 (16.2%) out of 326 patients had BCR. Independent predictors of BCR on multivariate analysis included: year of surgery PSM Operative time Association with BCR on Univariate analysis included: Prostate specific antigen (PSA) PSA density Pathological grade Pathological stage NVB release time Apical dissection time CONCLUSION PSM, prolonged operative time, and earlier year of surgery were independent predictors of BCR after RARP. These factors emphasize the role of surgeon’s experience in oncological outcomes post RARP. Single apical and anterior positive surgical margin had less impact on BCR compared to basal and posterolateral margins, and multiple positive margins.