Abstract: Background and purpose: Although both preoperative chemotherapy and preoperative radiochemotherapy are recommended by Gastric Cancer Treatment Guidelines for patients with locally advanced gastric cancer, priority treatment is still unclear. The aim of this study was to compare preoperative chemotherapy with preoperative radiochemotherapy. Methods: From Jun. 2007 to Oct. 2012, thirty patients diagnosed as having locally advanced gastric cancer were included in a phase Ⅱ clinical trial, and the patients were defined as chemotherapy group. All these patients received the 3-4 cycles of preoperative chemotherapy, and the regime was EOF (epirubicin, oxaliplatin and 5-FU). After surgery, additional 2-3 cycles of chemotherapy were given. From Apr. 2012 to Aug. 2014, 40 patients with locally advanced gastric cancer were included in a phase Ⅱ clinical trial, and the patients were defined as radiochemotherapy group. Patients received one cycle of SOX (S-1 and oxaliplatin) followed by concurrent radiation and S-1 chemotherapy, then underwent another cycle of SOX. Following surgery, additional four cycles of chemotherapy were administered. Finally, the efficacy and toxicity between preoperative chemotherapy and radiochemotherapy were compared. Results: Thirty patients completed the planned treatment of preoperative chemotherapy. Forty patients were included in the group of preoperative radiochemotherapy, and thirty-six patients were evaluable. There was no significant difference in baseline characteristics between chemotherapy and radiochemotherapy groups. There was no significant difference in clinical response rate or radical gastrectomy between two groups (41.7% vs 30.0%, 46.7% vs 66.7%, respectively). The pathological response rate in radiochemotherapy group was significantly higher than that of chemotherapy (50.0% vs 23.3%). Radiochemotherapy group had a higher rate of 3-year overall survival than chemotherapy group (41% vs 20%, P=0.009). Conclusion: The pathological response rate and 3-year overall survival rate of preoperative radiochemotherapy group were higher than those in preoperative chemotherapy group; the therapy-induced toxicity was more common in preoperative radiochemotherapy group than that in preoperative chemotherapy group.

Key words: Locally advanced gastric cancer, Preoperative chemotherapy, Preoperative radiochemotherapy, Prognosis