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.