Patients with stage II-IIIB gastric cancer who underwent curative D2 gastrectomy were randomly assigned ( 1:1 ) after surgery to receive adjuvant chemotherapy with capecitabine and oxaliplatin ( eight 3-week cycles of oral capecitabine 1000 mg/m ( 2 ) twice daily on days 1-14 plus intravenous oxaliplatin 130 mg/m ( 2 ) on day 1 ) for 6 months or observation alone .