Multicenter phase 3 trial of adjuvant chemoradiotherapy versus chemotherapy after D2 gastrectomy for gastric cancer

There is no consensus on the value of adding postoperative radiotherapy toe adjuvant chemotherapy after D2 gastrectomy (ie, gastrectomy with D2 lymphadenectomy) for gastric cancer. A phase 3 study at 5 centers in China compared outcomes with adjuvant chemoradiotherapy or chemotherapy after D2 gastrectomy in gastric cancer patients aged 18 to 70 years, with pathologic stage T4 or node-positive disease, and no evidence of metastasis. Patients were randomized to S-1 plus oxaliplatin (SOX; n=311) or SOX plus RT (n=309). The primary endpoint was 3-year disease-free survival rate. There was no evidence of a between-group difference in disease-free survival (SOX plus RT versus SOX: HR 0.98; 95% CI 0.73-1.33) or overall survival (0.86; 0.60-1.23). Treatment-related adverse events were similar between groups. The authors conclude that these findings do not support routine addition of adjuvant radiotherapy to chemotherapy among patients with D2-resected gastric cancer (visual abstract).