Fluorouracil and Leucovorin With or Without Irinotecan in Treating Patients Following Surgery for Stage III Colorectal Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed adenocarcinoma of the colon or intraperitoneal rectum
• * Stage III
• * Completely resected within the past 3-8 weeks
• * No gross or microscopic evidence of residual disease after surgery
• No rectal cancer requiring total meso-rectal resection or pre- or postoperative radiotherapy
• No prior curatively resected synchronous metastasis of colorectal cancer
• PATIENT CHARACTERISTICS:
• Age:
• 18 to 75
• Performance status:
• WHO 0-1
• Life expectancy:
• Not specified
• Hematopoietic:
• Absolute neutrophil count at least 2,000/mm\^3
• Platelet count at least 150,000/mm\^3
• Hemoglobin at least 10 g/dL
• Hepatic:
• Bilirubin no greater than upper limit of normal (ULN)
• AST and ALT no greater than 2.5 times ULN
• Alkaline phosphatase no greater than 2.5 times ULN
• Renal:
• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 60 mL/min
• Cardiovascular:
• No myocardial infarction with the past year
• No uncontrolled hypertension
• No high-risk uncontrolled arrhythmia
• No unstable angina pectoris
• Other:
• HIV negative
• No chronic diarrhea
• No current chronic inflammation or subobstruction of bowel after surgery
• No active uncontrolled infection
• No other prior or concurrent malignancy except curatively treated nonmelanoma skin cancer or carcinoma in situ of the cervix
• No psychological, social, familial, or geographical condition that would preclude follow-up
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 6 months after study participation
• PRIOR CONCURRENT THERAPY:
• Biologic therapy:
• Not specified
• Chemotherapy:
• No prior antineoplastic chemotherapy
• Endocrine therapy:
• Not specified
• Radiotherapy:
• See Disease Characteristics
• Surgery:
• See Disease Characteristics
• No prior celioscopic resection of primary tumor
• Other:
• At least 30 days since prior participation in another clinical trial with any investigational drug
• No other concurrent experimental drugs
• No other concurrent anticancer therapy