Resection margins after radical cystectomy at academic versus community cancer centers.

Abstract

315 Background: Positive surgical margins are reported in 1-5% of specimens following radical cystectomy (RC) for urothelial carcinoma of the bladder (UC). Negative margin (R0) resection correlates with improved overall survival (OS) following RC in individual institutional analyses compared to microscopic (R1) or grossly (R2) positive margins. The present study hypothesized that RC surgical resection margins vary between treating centers. Methods: Patients with UC undergoing RC were identified from the National Cancer Database (2004-2013). Treating centers were categorized as Academic Cancer Centers (ACC) and Community Cancer Centers (CCC). Rates of R0 vs. R1/2 resection were examined and logistic regression was performed to determine predictive factors for margin status. Results: A total of 40,187 patients were identified with a median age of presentation of 68 years. RC was performed equally at ACC (52%) compared to CCC (48%). Neoadjuvant chemotherapy was utilized more often at ACC (21%) compared to CCC (14%). RC at ACC was associated with higher rates of R0 resections (90%) compared to CCC (88%) (p < 0.001). On logistic regression, after adjusting for age, sex, ethnicity, comorbidities, disease stage, tumor grade, tumor size, and use of neoadjuvant chemotherapy, RC at ACC were associated with decreased risk of experiencing positive margins (OR = 0.79, 95% CI 0.74-0.85). Following multivariate regression, RC performed at ACC were associated with a significant hazard ratio (HR) for survival (HR = 0.88, 95% CI 0.85-0.91). Compared to all variables, R1/2 resection status was the next most significant predictor for poor survival in RC patients (HR = 1.83, 95% CI 1.75-1.91) after cancer stage. Conclusions: Surgical margin is an important, independent risk factor for mortality in patients undergoing RC for UC. RC at ACCs is associated with a higher rate of negative resection margins, suggesting that site of care may impact bladder cancer patient’s oncologic outcomes.