Intensity-modulated radiotherapy at high-volume centers improves survival in patients with esophageal adenocarcinoma receiving trimodality therapy.

The standard of care trimodality therapy for resectable locally advanced esophageal adenocarcinoma is complex and necessitates multidisciplinary care and expertise. In this work, it is hypothesized that facility clinical volume and utilization of intensity-modulated radiotherapy (IMRT) may influence outcomes. The National Cancer Data Base was queried for patients with cT1-4-N0-3 M0 esophageal adenocarcinoma undergoing trimodality therapy from 2004 to 2013 (n = 2445). All patients received chemoradiation followed by esophagectomy at a Commission on Cancer facility. The facility volume was categorized into tertiles: high-volume centers (HVCs) in the highest 25th percentile of cases per year, intermediate-volume centers (IVCs) with the next highest 25th percentile of cases, and low- and very low-volume centers (LVCs) in the lowest 50th percentile. Overall survival (OS) was estimated using Kaplan-Meier methods and Cox proportional hazard regression. Propensity score matching to balance patient characteristics between volume centers was performed. Subgroup analysis was done comparing IMRT versus 3D conformal radiotherapy. The median follow-up was 26 months. Treatment at an HVC (hazard ratio 0.63, 95% CI 0.49-0.81, P < 0.001) was found to be independently associated with improved overall survival in multivariable analysis. Three-year OS was 58.4%, 46.2%, and 47.5% for HVCs, IVCs, and LVCs, respectively (P < 0.001). Patients at HVCs were more likely to receive IMRT over 3D chemoradiation (CRT; OR 3.45, 95% CI 2.4-5.0, P < 0.001). Patients treated using IMRT at HVCs had improved OS compared to those treated at IVCs or LVCs (HR 0.68, 95% CI 0.52-0.90, P < 0.01), while patients treated with 3D CRT at HVCs had no survival advantage over those at IVCs or LVCs (P = 0.28). Patients with locally advanced esophageal adenocarcinoma treated with IMRT and at HVCs appear to have improved survival.