DISEASE CHARACTERISTICS: Histologically confirmed colorectal cancer metastatic to the liver No preoperative or intraoperative evidence of extrahepatic metastasis including clinical, radiographic, gross or microscopic evidence Tumors must be no more than 4 cm in diameter No more than 6 total tumors May have failed prior systemic chemotherapy Failure of 1 prior intra-arterial regimen excluding floxuridine, fluorouracil, or another fluoropyrimidine allowed if liver enzymes recovered No evidence of cirrhosis No gross ascites