Abstract D124: Racial differences in adverse pathology among men with prostate cancer at time of radical prostatectomy
Authors: Song Sikai , Cowan Janet , Zhao Shoujun , Cooperberg Matthew R , Carroll Peter R , Washington Samuel L 
Published: September 2020

Abstract
Objective: For black men, the concern that they are at greater risk of worse oncologic outcomes for prostate cancer compared to white counterparts may drive the greater push to surgery although reasons are likely multifactorial. While adverse pathology is associated with worse survival, data surrounding race-based differences in rates of adverse pathology is limited. We aim to examine the association between race and adverse pathology on surgical pathology among black and white men with prostate cancer. Methods: Using our institutional prospective oncologic database, we identified 3,826 patients diagnosed with prostate cancer since 1990 and underwent primary RP. Adverse pathology was defined as GS&gt;=4+3 or pT3/4 or pN1 on surgical pathology. Race was dichotomized as black or non-Hispanic white. Multivariable logistic regression modeling was utilized to examine the association between race and AP after adjusting for age, year of diagnosis, and clinical risk by UCSF-CAPRA category (low 0-2, intermediate 3-5, or high 6-10). PIRADS and GPS scores were not included in the regression models due to the limited sample size. There was no significant effect of interaction between race and CAPRA, therefore no interaction term was included in the regression analysis. Results: Of 3826 patients included, 3682 (96%) were white and 144 (4%) were black. At diagnosis, mean age was 60.4 years (SD 7.1), median PSA density was 0.19 (IQR 0.13-0.20), and most were intermediate- (44%) or high-risk (15%) by CAPRA. Mean GPS scores was 26.85 (SD 12). The majority of those who underwent prostate MRI had PIRADS 4-5 lesions (89% vs 7% PIRADS 3, 4% PIRADS 1-2). Most had a systematic ultrasound-guided prostate biopsy alone (98%, 1% TRUS targeted alone, 1% MRI-TRUS fusion biopsy). Compared to white counterparts, black men were younger (53% &lt;60 years vs 43%, p=0.02) with higher PSA density (PSAD 0.25 vs PSAD 0.19, p&lt;0.01), and a larger proportion was high-risk by CAPRA (24% vs 15%, p=0.03) at diagnosis. PI-RADS at diagnosis, Genomic Prostate Score at diagnosis, and rate of targeted biopsy at did not differ significantly by race. Post-RP, pathologic Gleason grade, T-stage, and positive surgical margins rates were similar between races (p&gt;0.05 for all). Nodal disease was more common in black men compared to white counterparts (8% vs 5%, p&lt;0.01) On multivariate analysis, black race was not associated with higher risk of AP (OR 1.04, 95% CI 0.67-1.61, p=0.86) after adjusting for age, clinical CAPRA score, and year of diagnosis. Conclusions: Black race was not associated with increased risk of AP at RP compared to white counterparts after adjusting for clinical factors. While race-based differences in oncologic outcomes exist, this study supports the growing body of research challenging the prior attribution of these differences solely on biology. Further investigation into how multiple factors such as biology/genetics, quality of care, social environment, and health-related behaviors may interact to contribute to these observations is warranted.
Citation Format: Sikai Song, Janet Cowan, Shoujun Zhao, Matthew R Cooperberg, Peter R Carroll, Samuel L Washington. Racial differences in adverse pathology among men with prostate cancer at time of radical prostatectomy [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D124.