RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of fluorouracil-uracil and leucovorin in treating elderly patients who have metastatic colorectal cancer.

OBJECTIVES: I. Determine the response rate of elderly patients with metastatic colorectal cancer treated with fluorouracil-uracil and leucovorin calcium (Orzel). II. Evaluate the toxicity profile of this regimen in this patient population. III. Compare response rates obtained in this study with those observed in recent phase III studies in younger patients.

OUTLINE: Patients receive oral fluorouracil-uracil and oral leucovorin calcium (Orzel) every 8 hours for 28 days. Courses repeat every 35 days in the absence of unacceptable toxicity or disease progression. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually thereafter.

PROJECTED ACCRUAL: A total of 20-55 patients will be accrued for this study within 1 year.

DISEASE CHARACTERISTICS: Histologically confirmed metastatic colorectal adenocarcinoma Measurable disease

PATIENT CHARACTERISTICS: Age: 75 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL AST or ALT no greater than 2.5 times upper limit of normal (ULN) Renal: Creatinine no greater than 1.5 times ULN Other: No serious infection No other serious underlying medical condition that would preclude protocol therapy No known hypersensitivity to fluorouracil-uracil or leucovorin calcium

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 6 months since prior adjuvant immunotherapy for colorectal cancer No concurrent immunotherapy Chemotherapy: At least 6 months since prior adjuvant chemotherapy for colorectal cancer No other concurrent chemotherapy Endocrine therapy: No concurrent hormonal therapy Radiotherapy: See Disease Characteristics At least 6 months since prior adjuvant radiotherapy for colorectal cancer Prior radiotherapy for locally symptomatic disease allowed Surgery: Prior surgery allowed Other: No prior therapy for metastatic disease No other concurrent investigational drugs No concurrent halogenated antiviral agents (e.g., lodenosine, fialuridine, FMAU, emtricitabine, and sorivudine)