This study was conducted to evaluate the clinical outcomes and toxicities of adjuvant treatment including S-1/cisplatin chemotherapy followed by S-1 based CRT.

Surgery is the only possible curative treatment of gastric cancer. However, the high recurrence rate makes gastric cancer a disease difficult to cure by surgery alone. Despite the benefit of CRT on local recurrence, the distant recurrence is the leading pattern of failure. We hypothesized that gastric cancer outcome could be improved using a more effective chemotherapy regimen. This study was conducted to evaluate the clinical outcomes and toxicity of adjuvant treatment including S-1/cisplatin chemotherapy followed by S-1 based CRT.

Inclusion Criteria:

• Age > 18 years

• Histologically proven gastric adenocarcinoma which is complete resected

• ECOG performance status of 1 or lower

• Adequate bone marrow function

  • absolute neutrophil count [ANC] ≥1,500µL, and platelets ≥100,000/µL

• Adequate kidney function (serum creatinine < 1.5 mg/dL)

• Adequate liver function (serum total bilirubin < 2 times the upper normal limit (UNL) serum transaminases levels <2 times UNL

• No prior chemotherapy

Exclusion Criteria:

• Other tumor type than adenocarcinoma
• Evidence of distant metastasis
• Past or concurrent history of neoplasm except for curatively treated non-melanoma skin cancer or in situ carcinoma of the cervix uteri
• Uncontrolled infection
• Unstable cardiac disease despite treatment, myocardial infarction within months prior to study entry
• History of significant neurologic or psychiatric disorders including dementia or seizures
• Other serious underlying medical conditions which could impair the ability of the patient to participate in the study
• Symptoms of gastrointestinal obstruction
• concomitant drug medication: The following drugs cause drug interaction with S-1.