The Impact of Adjuvant Postoperative Radiation Therapy and Chemotherapy on Survival After Esophagectomy for Esophageal Carcinoma

The objective of this study was to analyze the impact on overall survival (OS) from the addition of postoperative radiation with or without chemotherapy after esophagectomy, using a large, hospital-based dataset.Previous retrospective studies have suggested an OS advantage for postoperative chemoradiation over surgery alone, although prospective data are lacking.The National Cancer Data Base was queried to select patients diagnosed with stage pT3-4Nx-0M0 or pT1-4N1-3M0 esophageal carcinoma (squamous cell or adenocarcinoma) from 1998 to 2011 treated with definitive esophagectomy ± postoperative radiation and/or chemotherapy. OS was analyzed using the Kaplan-Meier method and compared using the log-rank test. Multivariate Cox regression analysis was used to identify covariates associated with OS.There were 4893 patients selected, of whom 1153 (23.6%) received postoperative radiation. Most patients receiving radiation also received sequential/concomitant chemotherapy (89.9%). For the entire cohort, postoperative radiation was associated with a statistically significant but modest absolute improvement in survival (hazard ratio 0.77; 95% CI, 0.71-0.83; P < 0.001). On subgroup analysis, postoperative radiation was associated with improved OS for patients with node-positive disease (3-yr OS 34.3 % vs 27.8%, P < 0.001) or positive margins (3-yr OS 36.4% vs 18.0%, P < 0.001). When chemotherapy usage was incorporated, sequential chemotherapy was associated with the best survival (P < 0.001). Multivariate analysis revealed that the addition of chemotherapy to radiation therapy, whether sequentially or concurrently, was a strong prognostic factor for OS.In this hospital-based study, the addition of postoperative chemoradiation (either sequentially or concomitantly) after esophagectomy was associated with improved OS for patients with node-positive disease or positive margins.