Multicenter phase 3 trial of perioperative versus adjuvant S-1 plus oxaliplatin for resectable stage II or III gastric cancer

The phase 3 RESONANCE trial, at 19 centers in China, compared perioperative (PC) versus adjuvant (AC) S-1 plus oxaliplatin (SOX) chemotherapy in patients with resectable stage II or III gastric cancer. Patients in the PC arm received two to four cycles of SOX followed by surgery and four to six cycles of SOX. Patients in the AC arm underwent upfront surgery followed by eight cycles of SOX. Primary end point was disease free survival rate at three years. The three-year DFS rate was 61.7% in the PC arm versus 53.8% in the AC arm (p=0.019) among all patients (panel a), was not significally different among the stage II patients (panel b), and was significant among the stage III patients (panel c). R0 resection rate was 94.9% in the PC arm versus 83.7% in the AC arm (p<0.0001). There were no differences between the arms in surgical outcomes or postoperative complications. The authors conclude that PC compared with AC resulted in better DFS among patients with resectable stage II or III gastric cancer, and was well-tolerated.