Background/aims: To validate the conventional Japanese grading of liver metastasis for no residual tumor resection in Stage IV colorectal cancer (CRC) with liver metastasis and to identify risk factors for postoperative recurrence.
Methodology: The subjects of this study were 1792 Stage IV CRC patients with liver metastasis.
Results: In 1792 cases, including unresectable cases, there was a significantly different prognosis by grade (P < 0.0001). In 421 R0 cases, there was no significant difference between Grade A and Grade B (P = 0.8527). In 381 cases without extra-hepatic metastasis, the prognosis was not significantly different among three grades. On multivariate analysis, carcinoembryonic antigen within 3 months from R0 operation (3M-CEA) was an independent risk factor regardless of extrahepatic metastasis. There was a significantly different prognosis (P < 0.0001) among Grade A', defined as a normal 3M-CEA level, Grade B', defined as Grade A or B and an abnormal 3M-CEA level, and Grade C', defined as Grade C and an abnormal 3M-CEA level.
Conclusions: The postoperative CEA level is an important risk factor during follow-up after curative resection in patients with liver metastatic colorectal carcinoma. The combination of the 3M-CEA level and conventional grading of liver metastasis is useful for follow-up of R0 resection cases.