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 or giving the drugs in different ways may kill more tumor cells.

PURPOSE: Randomized phase III trial to compare the effectiveness of chemotherapy administered via an implantable pump with a subcutaneous port for unresectable liver metastases in patients with resected primary colorectal cancer.

OBJECTIVES: I. Compare the efficacy of 2 schedules of fluorouracil/leucovorin given as a continuous intra-arterial infusion via an implantable pump vs. a subcutaneous port for unresectable liver metastases in patients with colorectal cancer. II. Compare the effect of each treatment on response rate, quality of life, and rate of technical complications in these patients.

OUTLINE: Randomized study. The following acronyms are used: CF Leucovorin calcium, NSC-3590 5-FU Fluorouracil, NSC-19893 Arm I: Single-Agent Chemotherapy with Drug Modulation. 5-FU; with CF. Weekly infusion via an implantable pump. Arm II: Single-Agent Chemotherapy with Drug Modulation. 5-FU; with CF. Weekly infusion via a subcutaneous infusion port. Arm III: Single-Agent Chemotherapy with Drug Modulation. 5-FU; with CF. Monthly infusion via an implantable pump. Arm IV: Single-Agent Chemotherapy with Drug Modulation. 5-FU; with CF. Monthly infusion via a subcutaneous infusion port.

PROJECTED ACCRUAL: A total of 336 patients will be entered in this multicenter study.

DISEASE CHARACTERISTICS: Primary colorectal cancer with unresectable liver metastases Less than 75% involvement of the liver Radical resection of primary colon or rectal tumor required No local recurrence or extrahepatic metastases No portal vein thrombosis, ascites, or cirrhosis

PATIENT CHARACTERISTICS: Age: 18 to 76 Performance status: Karnofsky 70%-100% Hematopoietic: WBC greater than 3,000 Platelets greater than 100,000 Hepatic: Bilirubin no greater than 4 mg/dL Alkaline phosphatase no greater than 1,200 U/L Coagulation tests normal Renal: Creatinine no greater than 2.5 mg/dL Other: No prior malignancy

PRIOR CONCURRENT THERAPY: See Disease Characteristics No prior intra-arterial chemotherapy for liver metastases No prior hepatic chemoembolization At least 3 months since fluorouracil