All patients with tumors that can be resected should undergo surgery. As many as 15% of selected stage III patients can be cured by surgery alone, particularly if lymph node involvement is minimal (<7 lymph nodes).
Postoperative chemoradiation therapy may be considered for patients with stage III gastric cancer. A prospective multi-institution phase III trial (SWOG-9008) evaluating postoperative combined chemoradiation therapy versus surgery alone in 556 patients with completely resected stage IB to stage IV (M0) adenocarcinoma of the stomach and gastroesophageal junction reported a significant survival benefit with adjuvant combined modality therapy.[Level of evidence: 1iiA] With a median follow-up of 5 years, median survival was 36 months for the adjuvant chemoradiation therapy group as compared to 27 months for the surgery-alone arm (P = .005). Three-year overall survival (OS) and relapse-free survival rates were 50% and 48%, respectively, with adjuvant chemoradiation therapy versus 41% and 31%, respectively, for surgery alone (P = .005). Because distant disease remains a significant concern, the aim of the Cancer and Leukemia Group B study (CALGB-80101), which is now closed, was to augment the postoperative chemoradiation regimen used in the SWOG-9008 trial, for example, and the preoperative chemotherapy and chemoradiation therapy regimen used, for example, in the RTOG-9904 trial, which is now completed.
Investigators in Europe evaluated the role of preoperative and postoperative chemotherapy without radiation therapy. In the randomized phase III trial (MRC-ST02), patients with stage II or higher adenocarcinoma of the stomach or of the lower third of the esophagus were assigned to receive three cycles of epirubicin, cisplatin, and continuous infusion 5-fluorouracil (ECF) before and after surgery or to receive surgery alone. Compared with the surgery group, the perioperative chemotherapy group had a significantly higher likelihood of progression-free survival (hazard ratio [HR] for progression, 0.66; 95% confidence interval [CI], 0.53–0.81; P < .001) and of OS (HR for death, 0.75; 95% CI, 0.60–0.93; P = .009). Five-year OS was 36.3%; 95% CI, 29 to 43 for the perioperative chemotherapy group and 23%; 95% CI, 16.6 to 29.4 for the surgery group.[Level of evidence: 1iiA]
Japanese investigators randomly assigned 1,059 patients with stage II or III gastric cancer who had undergone a D2 gastrectomy to receive either 1 year of S-1, an oral fluoropyrimidine not available in the United States, or follow-up after surgery alone. Patients were randomized in a 1:1 fashion. The 3-year OS rate was 80.1% in the S-1 group and 70.1% in the surgery-only group. The HR for death in the S-1 group, as compared with the surgery-only group, was 0.68 (95% CI, 0.52–0.87; P = .003).[Level of evidence: 1iiA]