PURPOSE:The study contained herein was aimed at finding some possible pathologic factors that have significance for the prediction of liver metastasis in colorectal cancer.METHOD:Resected specimens of colorectal cancer from 23 patients with liver metastasis and 30 patients without liver metastasis were subjected to pathologic study, including microscopic characteristics and proliferating cell nuclear antigen immunohistochemistry assay.RESULTS:Strongly positive expression of proliferating cell nuclear antigen was present in 65.21 percent (15/23) of the liver metastasis group, whereas it was found in only 20 percent (6/30) of the group without liver metastasis (P<0.005). Deeper invasion to the muscularis propria or serosa and less infiltration of lymphocytes surrounding the tumor were more frequently found in the liver metastasis group than in the other group (P<0.025).CONCLUSION:Extent of proliferating cell nuclear antigen expression, depth of invasion, and reaction of lymphocyte infiltration of the primary tumor could have predictive significance of colorectal cancer in liver metastasis.