A propensity-matched analysis comparing survival after esophagectomy followed by adjuvant chemoradiation to surgery alone for esophageal squamous cell carcinoma

Background: The role of adjuvant chemoradiation in esophageal cancer has been underestimated in the literature. This study was undertaken to determine whether adjuvant chemoradiation improves survival compared with surgery alone. Methods: Data of 1095 esophageal squamous cell carcinoma (ESCC) patients, including 679 in surgery alone group (group 1) and 416 in surgery followed adjuvant chemoradaition group (group 2), were obtained from the Taiwan Cancer Registry database. Propensity score matching (PSM) analysis was used to identify 147 well-balanced patients in each group for overall survival comparison. Results: After PSM, the 3-year survival rates and median survival were 44.9% and 27.2 (95% confidence interval [CI]: 17.6-40.3) months in group 2, which is significantly higher than that in group 1 (28.1% and 18.2 [95% CI: 14.3-24.5] months, P=0.0043). In the multivariate survival analysis, pT3/4 stage (Hazard Ratio [HR]: 2.03, 95% CI: 1.38-2.97, P<0.001), pN+ stage (HR: 1.83, 95% CI: 1.31-2.57, P=0.0004), tumor length more than 32mm (HR: 1.93, 95% CI: 1.33-2.79, P<0.001), R1/2 resection (HR: 1.75, 95% CI: 1.15-2.66, P=0.009), and adjuvant chemoradiation (HR: 0.57, 95% CI: 0.42-0.78, P<0.0001) were independent prognostic factors. Subgroup analysis suggested patients with pT3/4 stage, pN+ stage tumors, larger tumor size, poorly differentiated tumors, and R1/2 resections were more likely to demonstrate survival benefit from adjuvant chemoradiation. Conclusions: Compared with surgery alone, adjuvant chemoradiation provides a survival benefit to ESCC patients, especially those with pT3/4 stage, N+ tumors, larger tumor size, poorly differentiated tumors, and R1/2 resections.