A proposed classification system for liver metastasis from colorectal carcinoma

A proposed classification system for liver metastasis from colorectal carcinoma is presented. This proposed system utilizes the prognostic factors of the extent of hepatic involvement by metastasis at the time of laparotomy, performance status, preoperative serum alkaline phosphatase level, and the presence or absence of extrahepatic intraabdominal disease at the time of laparotomy. Because of the several different modes of treatment for liver metastasis from colorectal carcinoma, it is necessary that a liver classification system be adopted so that different treatment groups will be comparable. The proposed system utilizes the extent of hepatic involvement by metastasis at laparotomy with a division into three subsets of patients described by a Roman numeral. Roman numeral I represents less than or equal to 25 per cent involvement of the liver by metastasis; Roman numeral II represents greater than 25 per cent but less than or equal to 50 per cent involvement by liver metastasis, and Roman numeral III represents greater than 50 per cent involvement by liver metastasis. An Arabic subscript number is used to describe the patients' performance status. Alkaline phosphatase levels are described by a subscript letter with a representing less than two times normal alkaline phosphatase, b representing greater than two times, but less than four times normal levels, and c representing greater than four times normal levels. At the time of laparotomy extrahepatic intra-abdominal disease is represented by the superscript letter E.