ASCO 2017: Predictors of post-surgical race-specific prostate cancer progression

Chicago, IL ( Differences in prostate cancer (PCa) incidence and mortality for African American (AA) versus Caucasian American (CA) men may reflect tumor biology, comorbidity, treatment, follow-up care, and/or health care access. Dr. Jennifer Cullen presented a study including a racially diverse cohort of patients undergoing radical prostatectomy (RP). The study examined how race, comorbidity, and PSA doubling time (PSADT) impact PCa progression.  

Enrollees in the Center for Prostate Disease Research (CPDR) Multi-Center National Database from 1990-2014 who underwent RP within 12 months of PCa diagnosis were eligible. Biochemical recurrence (BCR) was defined as PSA ≥0.2 ng/mL post-RP. Comorbid conditions included coronary artery disease (CAD), cerebral vascular incident (CVI), Type II diabetes (DB), hypertension (HT), elevated cholesterol (EC), lung disease (COPD), prostatitis (PS), renal insufficiency (RI) and other cancer (OC). Multivariable Cox proportional hazards (PH) analysis was used to examine comorbid conditions (yes vs. no) and PSADT ( < 3, 3-8.9, 9-14.9, and ≥15 months) to predict BCR, controlling for age at RP, D’Amico risk stratum, pathology features, and adjuvant treatment. 

A total of 6,785 patients were eligible; 22% AA and 78% CA. Median age and follow-up was 62 and 6.1 years, respectively. Across race, comparable median follow-up time, distributions of pathologic features, and adjuvant treatments were observed. However, AA vs. CA patients had greater HT (53 vs. 39% p < 0.0001), DB (17 vs. 7%, p < 0.0001), and RI (3 vs. 1%, p = 0.002). Alternatively, CA vs. AA patients had greater CVD (10 vs. 7%, p = 0.0008) and OC (3 vs. 0.5%, p < 0.0001). Poorer BCR-free survival was demonstrated for AA vs. CA men (HR = 1.28, CI = 1.11, 1.48, p = 0.0009) adjusting for D’Amico risk stratum, pathology, and treatment. PSADT, not comorbidity, was a critical predictor of BCR, with poorest outcome at extremes: HR PSADT < 3 vs.  >= 15 months was 37.7, CI = 33.6, 46.5, p < 0.0001). 

Despite comparable health care access and distribution in clinical risk stratum and pathology features, race persisted in predicting poor PCa outcome. Disparate comorbidity for AA and CA men did not eliminate this difference. PSADT remained the most striking determinant of poor BCR-free survival.

Presented By: Jennifer Cullen, PhD, Center for Prostate Disease Research, Rockville, MD

Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre
Twitter: @GoldbergHanan

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 - Chicago, Illinois, USA