The objective of the trial is to compare disease-free survival between adjuvant XELOX alone vs XELOX with concurrent capecitabine and radiotherapy in curatively resected gastric cancer patients with D2 dissection.

Gastric cancer is one of the most common malignancies in China. Complete surgical resection is the only potentially curative therapy available to patients with gastric cancer. However, the overall survival results remain unsatisfactory. The main factor accounting for high mortality rate is the relapse after surgical resection. During the past few decades, the principle of combined modality treatment has been developed and applied in gastric cancer. Radiation therapy plus concurrent chemotherapy had demonstrated to be able to achieve a significant improvement in overall and disease-free survival according to Intergroup Trial 0116/Southwest Oncology Group 9008. Nevertheless, the result from Intergroup Trial 0116 study had been challenged by the fact that the surgical treatment applied in the trial was gastrectomy with limited lymph node dissection (D0 or D1) in 90% of cases. Therefore, it is debatable whether adjuvant chemoradiation therapy can confer survival benefit in patients with extensive lymph node dissection. In ARTIST study, the addition of concurrent capecitabine and radiotherapy to capecitabine and cisplatin chemotherapy did not significantly reduce recurrence after curative resection and D2 lymph node dissection in gastric cancer. In subgroup analysis of patients with positive pathologic lymphnodes, there was a statistically significant prolongation in disease-free survival in the concurrent treatment arm when compared with the chemotherapy alone arm. Furthermore, CLASSIC study showed that XELOX (oxaliplatin/capecitabine) combination given as adjuvant chemotherapy for stage II or III patients after D2 surgery could achieve a significant survival benefit. The standard treatment modality in gastric cancer after D2 dissection is still disputable. Thus, the assessment of the effect of adjuvant sequence chemoradiotherapy in D2 resected gastric cancer is essential.

Inclusion Criteria:

• Histologically proven gastric cancer; ≥ D2 resection
• Stage T1-4, N+
• 18 ≤ age ≤ 75
• Eastern Cooperative Oncology Group 0-2
• No distant metastasis
• Adequate bone marrow functions (absolute neutrophil count≥ 1,500/ul, blood platelet≥ 100,000/ul, haemoglobin≥ 10g/dl)
• Adequate renal functions(serum creatinine ≤ 1.5mg/dl)
• Adequate liver functions (serum bilirubin ≤ 1.5mg/dl, aspartate aminotransferase/alanine aminotransferase ≤ 3 times(normal value)
• Written informed consent

Exclusion Criteria:

• Previous history of immunotherapy, chemotherapy, radiotherapy for gastric cancer;
• Active infection requiring antibiotics;
• Pregnant, lactating women;
• Psychiatric illness, epileptic disorders;
• Concurrent systemic illness not appropriate for chemotherapy;
• Resection margin (+);
• History of other malignancy within 5 years except for non-melanoma skin cancer, cervix in situ carcinoma;
• D0, D1 resection;