Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed metastatic or locally recurrent
adenocarcinoma of the colon or rectum Bidimensionally measurable disease Lesions seen on
colonoscopic examination or barium studies, bone metastases, CNS lesions, CEA levels and
ascites are not considered measurable No CNS disease only CNS metastases with other sites
of measurable disease allowed provided appropriate therapy for CNS metastases has been
administered and patient is neurologically stable and does not require intravenous steroid
or anticonvulsant therapy

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 OR Zubrod 0-2 Life
expectancy: At least 12 weeks Hematopoietic: WBC at least 3,500/mm3 Absolute neutrophil
count at least 1,500/mm3 Platelet count at least 100,000/mm3 (no platelet transfusion
within 7 days) Hemoglobin at least 9.0 g/dL Hepatic: Bilirubin no greater than 1.5 mg/dL
Transaminases no greater than 2.5 times upper limit of normal Renal: Creatinine no greater
than 1.5 mg/dL OR Creatinine clearance at least 60 mL/min Other: Not pregnant or nursing
Negative pregnancy test Fertile patients must use effective contraception No significant
uncontrolled medical or psychiatric illness No serious active infection No other active
malignancy except nonmelanoma skin cancer or carcinoma in situ of the cervix unless
adequately treated and less than 30% risk of relapse

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent prophylactic use of growth
factors except for documented febrile neutropenia or sepsis Chemotherapy: At least 12
months since prior fluorouracil based adjuvant or neoadjuvant chemotherapy No more than 1
prior regimen No prior chemotherapy for advanced metastatic colorectal cancer No other
concurrent chemotherapy No concurrent investigational antineoplastic drugs Endocrine
therapy: See Disease Characteristics Radiotherapy: At least 4 weeks since prior
radiotherapy and recovered No prior radiotherapy to the only site of measurable disease No
concurrent radiotherapy Surgery: Not specified Other: See Disease Characteristics At least
30 days since prior investigational drug