Analysis of proliferative activity using antiproliferating cell nuclear antigen antibody in colorectal cancer

Using anti-PCNA antibody (PC10), an immunohistochemical study of the expression of PCNA in formalin-fixed and paraffin-embedded materials of colorectal cancer patients was performed and correlation of PCNA expression with clinicopathological findings and DNA ploidy pattern was studied. PCNA labeling rate (PCNA LR) was estimated in the advancing margin of the tumor and ranged from 23.8% to 77.9%. There was a significant difference in lymphatic vessel invasion, liver metastasis and Dukes' stage between the groups with high (> 48.7) and low (< 48.7) PCNA LR (P < 0.05). No differences were seen in tumor size, histological type, lymph node metastasis or DNA ploidy pattern. In patients with younger age, infiltration to neighboring organs, a high degree of venous invasion, and peritoneal dissemination, the frequency of high PCNA LR tended to be higher (P < 0.1). The results above suggest that a high proliferative activity as defined by evaluation of the PCNA LR at the advancing margin of the tumor may be one of the parameters of malignant potential and helpful as a predictor of liver metastasis in colorectal cancer.