Immunohistological Characteristics of Colorectal Polyps with Advanced Colorectal Carcinoma

The purpose of this study was to investigate the influence of the coexistence of advanced colorectal carcinoma on cell proliferation and changes in oncogene expression in the epitherial cells of colorectal polyps. We examined relationship between the degree of cell differentiation of the polyps and the labeling indices of proliferating cell nuclear antigen (PCNA L.I.) and expression of p53 protein in 57 colorectal polyps and normal mucosas from 32 patients with advanced colorectal carcinoma (ACC) obtained by surgical procedure or endoscopic polypectomy. Material used for control study including 49 colorectal polyps from 35 patient without ACC and 7 normal mucosas from 7 patients without any colon tumor. PCNA L.I. expression was closedly correlated with the degree of epithelial cell differentiation of the polyps in the both groups. The PCNA L.I. levels of expression in patients with ACC were higher than those of patients without ACC except in cases of normal mucosa or the carcinomas had invaded to the submucosal layer. Moreover, positive cell rates of the polyps also correlated closedly with the degree of epithelial cell differentiation of the polyps. Consequently it was suggested that the epithelial cells of the polyps with ACC had higher proliferation livels and more frequent changes of oncogene expression than those of polyps without ACC.