Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed cancer of the colon or
rectum that is locally advanced or metastatic Primary lesion was or is located in the
large bowel as confirmed by endoscopy, radiology, or surgery Radiologic or clinical
evidence of metastasis subsequent to resection does not require histologic or cytologic
confirmation unless: Interval between primary surgery and development of metastasis is
greater than 5 years OR Primary cancer was Dukes' A or B1 Ineligible for potentially
curative therapy, e.g.: Surgical resection of a limited hepatic or pulmonary metastasis
Irradiation of locally recurrent colon or rectal cancer No or minimal symptoms related to
the cancer, i.e.: No persistent pain requiring regular narcotic analgesia No persistent
fever greater than 38 degrees C No symptomatic bowel obstruction No persistent nausea
requiring medication No weight loss of greater than 5 kg over the previous 3 months unless
clearly not associated with the cancer (e.g., associated with surgery or intercurrent
illness) Symptomatic relapse/metastases rendered asymptomatic by secondary surgery or
radiotherapy are eligible provided the patient remains asymptomatic for at least 6 weeks
following such treatment No CNS metastases No significant ascites, pleural effusion, or
pericardial effusion

PATIENT CHARACTERISTICS: Age: Adult under 80 (i.e., of legal age to sign own informed
consent according to institutional policy) Performance status: Karnofsky 90-100% ECOG 0
Hematopoietic: Granulocytes at least 1,500/mm3 Platelet count at least 100,000/mm3
Hepatic: Bilirubin no greater than upper limit of normal Renal: Creatinine less than 2.26
mg/dL Cardiovascular: No arrhythmia Other: No infection No other medical condition that is
uncontrolled or could be aggravated by the protocol therapy No prior or concurrent second
cancer except: Nonmelanomatous skin cancer In situ cervical cancer No pregnant women
Adequate contraception required of fertile patients Blood/body fluid analyses to determine
eligibility and quality-of-life questionnaire completed within 14 days prior to
randomization; imaging studies of sites of disease completed within 28 days prior to
randomization

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior
chemotherapy for metastatic disease or local recurrence Prior fluorouracil-based or other
adjuvant therapy allowed At least 6 months required between completion of therapy and
documentation of metastasis or recurrence Endocrine therapy: Not specified Radiotherapy:
Prior radiotherapy allowed Surgery: Prior surgery allowed