S0030: Capecitabine in Treating Older Patients W/Metastatic or Recurrent Colorectal Cancer That Cannot Be Surgically Removed

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed metastatic or recurrent colorectal cancer not amenable to surgical resection * Measurable disease * No known brain metastases by MRI or CT scan PATIENT CHARACTERISTICS: Age * 70 and over OR * 18 to 59 Performance status * Zubrod 0-2 Life expectancy * Not specified Hematopoietic * Absolute granulocyte count at least 1,000/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Bilirubin no greater than 2 times upper limit of normal (ULN) * SGOT (serum glutamate oxaloacetate transaminase) or SGPT (serum glutamate pyruvate transaminase) no greater than 2 times ULN Renal * Creatinine no greater than 2 times ULN * Creatinine clearance greater than 50 mL/min Other * Not pregnant or nursing * Fertile patients must use effective contraception * HIV negative * No known seizure disorder * No other malignancy except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, adequately treated stage I or II cancer currently in complete remission, or any other cancer for which the patient has been disease free for 5 years PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * No prior chemotherapy for advanced cancer * Prior adjuvant chemotherapy allowed provided recurrence occurred more than 1 year after the last treatment Endocrine therapy * Not specified Radiotherapy * Not specified Surgery * Not specified Other * At least 4 weeks since …