Randomized, multicenter, controlled evaluation of S-1 and oxaliplatin (SOX regimen) as neoadjuvant chemotherapy for advanced gastric cancer patients (RESONANCE trial).

Abstract

90 Background: RESONANCE trial aims to improve 3-year disease-free survival (DFS) for patients treated with neoadjuvant chemotherapy and D2 surgery with chemotherapy postoperatively. We also evaluated the postoperative complications with and without preoperative chemotherapy to reveal the safety of SOX regimen. Methods: In this phase III multicenter study, patients with American Joint Committee on Cancer(AJCC,7thed)stage II-IIII advanced gastric cancer are treated with two to four cycles of preoperative SOX chemotherapy, followed by gastrectomy with D2 lymphadenectomy, and then another four to six postoperative cycles of SOX chemotherapy. Surgical and pathological quality control is performed. The primary endpoint is 3-year DFS, secondary endpoints are 3-year OS, D2/R0 rate, and toxicity and recurrence risk. The RESONANCE trial has been registered internationally, and twenty hospitals have participated in this trial. Results: Between February 2012 and to August 2013, 128 patients were enrolled in the neoadjuvant group , 103 patients were enrolled in the adjuvant group. Seventy-four of 128 patients underwent gastrectomy with D2 lymphadenectomy after preoperative chemotherapy. In these 74 patients, 52 (70%) patients had clinical tumor response and 10 (14%) patients achieved histological response. Operative mortality was never encountered. R0 resection rate was 90.5% after neoadjuvant chemotherapy compared with 94.2% in adjuvant group (p=0.23). Postoperative complication rates in neoadjuvant and adjuvant groups were 33.8% and 37.9% respectively (p=0.58). Conclusions: Results of this study will demonstrate whether neoadjuvant chemotherapy strategy will be superior to adjuvant chemotherapy when combined with D2 surgery for AJCC stage II-III gastric cancer patients. Furthermore, it might be an important clinical evidence to verify benefit of neoadjuvant chemotherapy in advanced gastric cancer. Clinical trial information: NCT01583361.