A Phase II Study of Tegafur-Uracil as Maintenance Chemotherapy in Patients With Stage II of Colon Cancer

Inclusion Criteria To be eligible for inclusion, each subject must fulfill all of the following criteria: 1. pathologically confirmed adenocarcinoma of the colon with stage II disease; 2. complete resection of primary tumor; 3. detection of low level microsatellite instability (MSI-L) or microsatellite stable (MSS) in resected tumor sample; 4. no prior chemotherapy or radiotherapy for colon cancer; 5. ECOG performance status 0 to 1; 6. age of 20 years or older; 7. able to start the study treatment within 8 weeks after surgery; 8. able to understand and willingness to sign a written informed consent document. Exclusion Criteria Subjects who fulfill any of the following criteria will be excluded from the trial: 1. Severe postoperative complications; 2. inadequate hematopoietic function which is defined as below: 1. hemoglobin \< 9 g/dL; 2. absolute neutrophil count (ANC) ≤ 1,500/mm3; 3. platelet count \< 100,000/mm3; 3. inadequate hepatic function which is defined as below: 1. total bilirubin \> 2 times upper limit of normal (ULN); 2. hepatic transaminases (ALT and AST) \> 2.5 x ULN; 4. inadequate renal function which is defined as below: a.creatinine \> 1.5 x ULN; 5. significant medical conditions that is contraindicated to study medication or render patient at high risk from treatment complications based on investigator's discretion; 6. other malignancy within the past 5 years except for adequately treated basal or squamous cell skin cancer or cervical cancer in situ; 7. participation in another clinical trial with any investigational drug within 30 days prior to entry; 8. pregnant women or nursing mothers, or positive pregnancy test for women of childbearing potential. Patients with childbearing potential should have effective contraception for both the patient and his or her partner during the study.