ANALYSIS OF PROGNOSTIC RISK-FACTORS IN HEPATIC RESECTION FOR METASTATIC COLORECTAL-CARCINOMA WITH SPECIAL REFERENCE TO THE SURGICAL MARGIN

Background Liver resection for metastatic colorectal cancer has been e stablished. Nevertheless, it is still controversial whether the surgic al margin from the tumour edge to the cut surface of the liver is a si gnificant prognostic factor in hepatic resection for colorectal metast atic liver cancer. Methods To clarify the prognostic risk factors in h epatic resection for colorectal metastasis, univariate and multivariat e analyses were performed. Between April 1985 and April 1995, 31 patie nts underwent curative hepatic resection for metastatic colorectal can cer. The clinical and pathological factors were examined retrospective ly. Results Overall 1-, 3- and 5-year survival rates of the patients w ere 92, 42 and 39 per cent respectively. Pathological study of 16 rese cted specimens with a solitary liver tumour revealed hepatic vein inva sion by cancer cells in two of 16 cases, portal vein invasion in three , microsatellite lesions in two and biliary tract invasion in six case s. In resected specimens with a solitary tumour measuring less than 4 cm in diameter, one of these factors was observed in only two of nine cases, whereas in specimens with a solitary tumour measuring more than 4 cm in diameter, these factors were observed in six of seven patient s (P < 0.05). The distance from the tumour edge to the intrahepatic in vasion was less than 10 mm. With univariate analysis, tumour size of 4 cm or more in diameter, an interval of 6 months or less between color ectal and hepatic resection, four or more gross rumours, bilobar invol vement and a resection margin from the tumour of less than 10 mm were found to be significant factors indicating a poor prognosis. Cox's pro portional hazards model identified a tumour of 4 cm or more in diamete r and a resection margin from the tumour of less than 10 mm as poor pr ognostic factors (P<0.05). Conclusion In treating metastatic colorecta l cancer to the liver, the surgical margin should be more than 10 mm b ecause occult intrahepatic invasion was always found to be located wit hin 10 mm from the edge of the tumour.