This study is designed to compare the three chemotherapy regimens(TEGAFOX Sequential S-1 or SOX Sequential S-1 or SOX non-Sequential S-1) for postoperative patients with gastric cancer, observe and record the efficacy and tolerance,to evaluate which regimen is better.

Inclusion Criteria:

• 75≧Age≧18
• Histologically or cytologically confirmed gastrointestinal cancer
• Stage Ⅱ or Ⅲ or Ⅳ
• ECOG ≦2
• Accept the gastric cancer radical resection
• Life expectancy of at least three months
• Written informed consent to participate in the trial

Exclusion Criteria:

• History of severe hypersensitivity reactions to the ingredients of S-1\TF\5-FU/calcium folinate or oxaliplatin

• Inadequate hematopoietic function which is defined as below:

  • white blood cell (WBC) less than 5x10^9/L
  • absolute neutrophil count (ANC) less than 2x10^9/L
  • platelets less than 100*10^9/L

• Inadequate hepatic or renal function which is defined as below:

  • serum bilirubin greater than 2 times the upper limit of normal range
  • alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 2.5 times the ULN if no demonstrable liver metastases or greater than 5 times the ULN in the presence of liver metastases
  • blood creatinine level greater than 2 times ULN

• Presence of peripheral neuropathy

• Receiving a concomitant treatment with other fluoropyrimidine drug or flucytosine drug

• Women who is pregnant or lactating or fertile women of child-bearing potential unless using a reliable and appropriate contraceptive method throughout the treatment period (Including male)

• Psychiatric disorder or symptom that makes participation of the patient difficult;

• Concomitant illness that might be aggregated by active, non-controlled disease such as congestive heart failure, ischemic heart disease, uncontrolled hypertension or arrhythmia with in six months

• Severe complication(s), e.g., paresis of intestines, ileus, radiographically confirmed interstitial pneumonitis or pulmonary fibrosis, glomerulonephritis ,renal failure, poorly-controlled diabetes