Matthew Gettman

MP77-17 IMPACT OF TIME FROM BIOPSY TO SURGERY ON COMPLICATIONS, FUNCTIONAL AND ONCOLOGIC OUTCOMES FOLLOWING RADICAL PROSTATECTOMY

on AS must undergo PSA testing and repeated biopsies over time in all proposed protocols and patients are subjected to discomfort and anxiety as well as to the complications of repeated biopsies. We tried to identify the predictors of progression-free survival (PFS) at a single institution AS program in order to identify patients in whom repeated biopsies could be avoided or reduced in frequency. METHODS: Between 2009 and 2016, 235 consecutive patients affected by low-risk PCa according to PRIAS criteria (cT1/T2a; PSA<10 ng/ml; PSA density <0.2; Gleason score <7; <3 positive cores) were enrolled in our AS program. Tumor progression was defined as pathological upgrading (Gleason >6 or >2 positive cores) at repeated yearly biopsies. First, Kaplan-Meier analyses were used to quantify progression-free survival at 1, 3 and 5 years, respectively. Second, we identified patients who were progression-free at 3 years of follow-up. Finally, univariable and multivariable logistic regression analyses were used to predict 3-year PFS. Covariates consisted of age, total PSA, clinical stage (cT) and number of positive cores at the time of enrolment as well as negative (no cancer) 1-year biopsy. RESULTS: Progression-free survival rate was 85%, 55%, and 40% at 1, 3 and 5 years, respectively. Median follow-up was 19 months. Overall, 56 (23.8%) patients were progression-free at 3 years of followup. Median number of cores at enrolment in AS program was 16 (IQR: 14-20), while median number of cores at first-year biopsy was 18 (IQR: 14-20). At univariable analyses, total PSA and negative 1-year biopsy were significant predictors of 3-year PFS (all p<0.05). Patients with negative biopsy at 1 year had a 3-year PFS of 75.8 vs. 29.0% in those with positive biopsy at 1-year. These results were confirmed at multivariable analyses, where a negative 1-year biopsy represented the only independent predictor of 3-year PFS (OR: 2.47; p1⁄40.04). CONCLUSIONS: The first biopsy after enrolment in AS program is an important predictor of PCa progression in the first 3 years in men on AS. Negative findings at 1-year biopsy suggest a high chance of 3-year PFS. Patients with negative 1-year biopsy could be followedup with less stringent biopsy protocol, in order to reduce possible biopsy-related side effects and discomfort.

MP93-16 IMPACT OF OBESITY ON PROSTATE CANCER RECURRENCE AFTER RADICAL PROSTATECTOMY

INTRODUCTION AND OBJECTIVES: When operating deep in the abdomen and pelvis, excess fat can interfere with accessing key anatomical structures and create difficulty in dissection and reconstruction. Since intraperitoneal fat is avoided during extraperitoneal robot assisted radical prostatectomy (eRARP), some Urologists have advocated this approach over its transperitoneal counterpart (tRARP) when operating on morbidly obese men (BMI>40). Herein, we aim to compare outcomes of eRARP vs. tRARP in the morbidly obese. METHODS: A chart review of patients who have undergone robot assisted radical prostatectomy (RARP) at a tertiary care academic center from July 1, 2003 through April 30, 2016 was undertaken. Patients with BMI >40 were identified. Those with concomitant inguinal hernia repair were excluded. The resulting eRARP and tRARP groups were compared for demographic, clinical and pathologic characteristics. Regression analysis was performed between the groups with Age, BMI, ASA score and D’Amico classification as selected covariates. RESULTS: 3168 patients underwent RARP during this time period, of which 82 patients met our inclusion and exclusion criteria; each group comprised 41 patients. No differences were noted in age, BMI, ASA score or pre-operative PSA. The tRARP group had a higher clinical stage (p1⁄40.016), biopsy Gleason score (p1⁄40.007) and D’Amico risk category (p<0.00001). The tRARP group had a higher rate of pelvic lymph node dissection (PLND, p<0.00001). No differences were noted in rate of nerve sparing. No differences were noted in OR time, estimated blood loss (EBL), length of stay (LOS) or time to catheter removal (TCR). No differences were noted in surgical margin status or overall complications (either calculated as binary or total number). On regression analysis, no differences were noted in complications, OR time, LOS, TCR or EBL. CONCLUSIONS: In this cohort, surgical approach (eRARP vs. tRARP) did not affect intraor peri-operative outcomes in morbidly obese men undergoing RARP so surgeons should tailor their approach based on comfort level.

PD71-03 NOVEL DNA METHYLATION MARKERS FOR ACCURATE PROGNOSTIC ASSESSMENT OF PROSTATE CANCER: DISCOVERY AND EARLY VALIDATION

INTRODUCTION AND OBJECTIVES: The prostate health index (PHI) is superior to PSA and other PSA-derivatives for the detection of prostate cancer (PCa). We sought to explore the utility of PHI density for the detection of clinically-significant PCa in a contemporary cohort of men presenting for diagnostic workup of PCa. METHODS: The study cohort includedpatientswith elevatedPSA (>2 ng/mL) and negative digital rectal examination who underwent PHI testing and prostate biopsy at our institution in 2015. Serummarkers were prospectively measured per standard clinical pathway. PHI was calculated as [([-2]proPSA/free PSA) x (PSA)], and density calculations were performed using prostate volume as determined on transrectal ultrasound. Logistic regression was used to assess the ability of serum markers to predict clinically-significant PCa, defined as any Gleason score 7 cancer or Gleason score 6 cancer in >2 cores or >50% of any positive core. RESULTS: Of 118 men with PHI testing who underwent biopsy, 47 (39.8%) were found to have clinically-significant PCa on biopsy. The median PHI density was 0.70 (IQR 0.43-1.21); it was 0.53 (IQR 0.360.75) in men with negative biopsy or clinically-insignificant PCa and 1.21 (IQR 0.74-1.88) in men with clinically-significant PCa (p<0.001). Clinically-significant PCa was detected in 3.6% of men in the first quartile of PHI density (<0.43), 36.7% of men in the interquartile range (0.43-1.21) of PHI density, and 80.0% of men with PHI density >1.21 (p<0.001). Using a threshold of 0.43, PHI density was 97.9% sensitive and 38.0% specific for clinically-significant PCa, and 100% sensitive for Gleason score 7 disease. Compared to PSA (AUC 0.52), PSAD (AUC 0.70), % free PSA (AUC 0.75), and PHI (AUC 0.76), PHI density demonstrated the highest discriminative ability for clinically-significant PCa (AUC 0.84). CONCLUSIONS: Based on this prospective single-center experience, PHI density could be used to avoid 38% of unnecessary biopsies while failing to detect only 2% of clinically-significant cancers.