Combination Chemotherapy in Treating Patients With Recurrent or Metastatic Colorectal Cancer

DISEASE CHARACTERISTICS: Histologically proven locoregionally recurrent or metastatic adenocarcinoma of the colon or rectum Histologic or cytologic proof of adenocarcinoma consistent with colorectal cancer in a solitary lesion if plasma carcinoembryonic antigen level is no greater than normal Metastases not limited to bone, pleural effusion, or ascites Surgically resectable metastases not eligible No symptomatic brain metastasis At least one bidimensionally measurable lesion measuring at least 20 mm in one diameter outside a previously irradiated area PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 3 times upper limit of normal Renal: No uncontrolled hypercalcemia Cardiovascular: No significant cardiac disease Pulmonary: No severe respiratory illness Neurologic: No peripheral sensory neuropathy Other: No uncontrolled infection or chronic disease No second malignancy except basal cell carcinoma of the skin or in situ carcinoma of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy for locoregionally recurrent or metastatic colorectal cancer No concurrent prophylactic growth factor Chemotherapy: No prior chemotherapy for locoregionally recurrent or metastatic colorectal cancer At least 6 months since adjuvant chemotherapy Endocrine therapy: No prior hormone therapy for locoregionally recurrent or metastatic colorectal cancer No concurrent corticosteroids Radiotherapy: See Disease Characteristics No prior radiotherapy for locoregionally recurrent or metastatic colorectal cancer Concurrent localized analgesic radiotherapy of a bone lesion permitted unless indicative of disease progression Surgery: No prior surgery for locoregionally recurrent or metastatic colorectal cancer Other: No other concurrent investigational drug