Is adjuvant chemotherapy necessary for early gastric cancer?

Objective: To quantify the potential benefit of adjuvant chemotherapy (ACT) with respect to survival, and to identify factors for predicting prognoses in early gastric cancer patients. Methods: Patients with pT1 gastric cancer (GC) who underwent radical resection with D2 lymphadenectomy were retrospectively analyzed. Based on lymph node metastasis (LNM) status and treatment regimens, patients were classified into groups, and clinicopathological variables, overall survival (OS), and disease-specific survival (DSS) were compared. Results: Of 1,050 enrolled patients, 151 patients (14.4%) had a positive LNM status. Submucosal invasion, undifferentiated state, tumor size > 2 cm, ulceration, and lymphovascular invasion were independent risk factors for LNM using multivariate analyses. The 5-year OS of all patients was 96.4%. HER2 positive, perineural invasion, and LNM were independent factors for worse survival. Patients with pT1N3 GC had a worse 5-year OS and DSS than pT1N0, pT1N1, and pT1N2 patients (P < 0.001). The 5-year OS and DSS for pT1N1 patients showed no significant difference between ACT and surgery only patients. For pT1N2 patients, the 5-year OS and DSS showed no significant difference between S-1 and Xelox treatments. For pT1N3 patients, 7 (36.8%) received S-1, while 12 (63.2%) received Xelox treatment. Patients receiving Xelox treatment showed a better 5-year OS (75.0% vs. 14.3%) and DSS (81.8% vs. 20.0%) than patients receiving S-1 (P < 0.05). Conclusions: Curative surgery only was adequate for patients with pT1N0 and pT1N1. Xelox showed no survival benefits for pT1N2 patients. Therefore, S-1 is the optimal choice for pT1N2 patients, when considering adverse effects. Xelox is recommended for pT1N3 patients.