Chemotherapy With or Without Isolated Hepatic Perfusion With Melphalan in Treating Patients With Colorectal Cancer That Has Spread to the Liver

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed metastatic colorectal cancer of the parenchyma of the liver * No evidence of extrahepatic disease (limited resectable extrahepatic disease allowed) * Unresectable liver metastasis, as defined by the following: * More than 3 sites of disease * Bilobar disease * Tumor abutting major vascular or ductal structures * Measurable disease * No biopsy-proven cirrhosis or evidence of significant portal hypertension manifested by ascites, esophageal varices, or collateral vessels around organs drained by the portal venous system PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * ECOG 0-2 Life expectancy: * Not specified Hematopoietic: * Platelet count greater than 100,000/mm\^3 * Hematocrit greater than 27.0% * WBC greater than 3,000/mm\^3 Hepatic: * Bilirubin less than 2.0 mg/dL * PT no greater than 2 seconds over upper limit of normal * Elevations in transaminases secondary to metastatic disease allowed * No veno-occlusive disease * No active chronic hepatitis * Hepatitis B or C allowed provided there is no evidence of cirrhosis Renal: * Creatinine no greater than 1.5 mg/dL OR * Creatinine clearance greater than 60 mL/min Cardiovascular: * No ischemic cardiac disease * No prior congestive heart failure with LVEF less than 40% Pulmonary: * No chronic obstructive pulmonary disease or other chronic pulmonary disease with pulmonary function test less than 50% of predicted Ot…