In this study, the relationship between DPD and the effects of S-1 combined with oxaliplatin chemotherapy were investigated in 200 patients with gastrointestinal carcinoma.

A new oral DPD inhibitory fluoropyrimidine (DIF), S-1, is reportedly effective against gastrointestinal carcinoma. In this study, the relationship between activity of DPD in peripheral blood and the effects of chemotherapy were investigated in 200 patients treated with first-line S-1 combined with platinum chemotherapy for gastrointestinal carcinoma.

Inclusion Criteria:

• Age ≧18;
• Histologically or cytologically confirmed gastrointestinal cancer；
• ECOG ≦2;
• Physician's intention to treat with S-1 combined with platinum regimen on disease status and clinical judgment;
• 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 or oxaliplatin;

• Inadequate hematopoietic function which is defined as below:

  • white blood cell (WBC) less than 3,500/mm^3
  • absolute neutrophil count (ANC) less than 1,500/mm^3
  • platelets less than 80,000/mm^3

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

  • serum bilirubin greater than 1.5 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;

• Known DPD deficiency;

• Receiving a concomitant treatment with sorivudine or Brivudine within two months;