348 MULTI-INSTITUTIONAL PREDICTORS OF GLEASON SCORE UPGRADING IN A LARGE AFRICAN-AMERICAN POPULATION

INTRODUCTION AND OBJECTIVES: Gleason score from biopsy specimens is important for prostate cancer risk stratification and influences treatment decisions. Gleason score upgrading (GSU) between biopsy and surgical pathology specimens has been reported as high as 50% and presents a challenge in counseling low-risk patients. While recent studies have investigated predictors of GSU, populations in these studies have been largely Caucasian. We report our analysis of predictors of GSU in a large urban African-American population across two institutions. METHODS: A total of 959 patients with DAEAmico low risk prostate cancer underwent radical prostatectomy at our institution between January 2005 and July 2012. Race, age, PSA, body mass index, CAPRA score and TRUS biopsy characteristics (number of reported biopsy cores showing adenocarcinoma, highest percent of biopsy core positive for adenocarcinoma, and measured TRUS prostate volume) were analyzed with both univariate and multivariate analysis to identify significant predictors of GSU while controlling for clinical parameters. RESULTS: Of the 959 cases, 288 (30.0%) were upgraded on final pathologic specimen, while the remaining 671 had the same Gleason sum as the preoperative biopsy. (Table 1) Our patient population consisted of 40.0% African-Americans and 42.0 of the AfricanAmerican population showed GSU. Mean Gleason score for those who were upgraded was 7.24. Upon univariate and multivariate analysis, BMI, total positive biopsy cores, percent of core involved with cancer, CAPRA score, and smaller prostate volume were statistically significant in the upgraded cohort. Patients who upgraded tended to be of higher BMI and of African-American descent in our analysis. Transrectal biopsies of these patients showed smaller prostate volumes but higher cores positive with high % disease per core. CONCLUSIONS: More than a quarter of low-risk prostate cancer patients were upgraded on final pathology in our series. Higher BMI and CAPRA score, smaller prostate volume and total number of cores and percent of cores involved were independent predictors of GSU. Individuals, especially African-Americans, with those clinical parameters may harbor occult high-grade disease and should be carefully counseled on treatment decisions.