Efficacy of adjuvant chemotherapy on overall survival in patients with lymph node-positive esophageal squamous cell carcinoma: Is oral chemotherapy promising?

Background The role of adjuvant chemotherapy in patients with pathological lymph node-positive (pN+) resectable esophageal squamous cell carcinoma (ESCC) remains unclear. We aimed to explore whether adjuvant chemotherapy could improve the overall survival (OS) of patients with pN+ ESCC and whether oral chemotherapy could be used as an alternative to intravenous chemotherapy. Methods The patients were divided into two groups: a surgery plus chemotherapy group (S + CT group, 400 patients) and a surgery alone group (S group, 582 patients). Propensity score matching (PSM) was used to create patient groups that were balanced across several covariates (n = 331 in each group). The survival rates of patients receiving oral chemotherapy (69 patients with S-1 and 68 patients with tegafur tablets) and intravenous chemotherapy (263 patients) were compared using the Kaplan-Meier method. Results In the overall study cohort, the 3-year OS was significantly higher in the S + CT group than in the S group (66.3% vs. 49.9%, p < 0.001). These data were confirmed in the matched groups (3-year OS, 72.9% vs. 62.0%, p < 0.001). Multivariate Cox regression analysis in the matched samples showed that adjuvant chemotherapy was an independent prognostic factor for ESCC (HR: 0.62, 95% CI: 0.50-0.76, p < 0.001). Patients who received oral chemotherapy had a similar OS as patients who received intravenous chemotherapy. Conclusions Adjuvant chemotherapy could significantly improve the OS of patients with pN+ ESCC, and oral chemotherapy drugs might be a better option because of their similar efficacy but fewer side effects than intravenous chemotherapy. This conclusion warrants further study in prospective, randomized controlled trials.