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

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 and giving them in different ways may kill more tumor cells. It is not yet known which chemotherapy regimen is most effective for colorectal cancer that has spread to the liver. PURPOSE: Randomized phase III trial to compare the effectiveness of combination chemotherapy with or without isolated hepatic perfusion with melphalan in treating patients who have colorectal cancer that has spread to the liver.