Immunohistochemical detection of proliferating cells in colorectal carcinomas and adenomas with the monoclonal antibody Ki-67. Preliminary data.

Twenty one cases of colorectal adenocarcinoma and six of adenoma have been studied using the monoclonal antibody Ki-67 which recognizes a nuclear antigen expressed by proliferating cells (PC). The quantitative evaluation of the stained nuclei showed that PC were more numerous in carcinomas than in adenomas although the difference did not reach a significant level. In each tumour, heterogeneity was noted. Furthermore, the superficial areas of both carcinomas and adenomas contained a greater number of PC than the deep. No difference was noticed in the various types and grades of differentiation for carcinomas. This preliminary report, compared with the only previous study of Shepherd et al. (1988) outlines the interest of the monoclonal antibody Ki-67 in the evaluation of growth fractions in colorectal tumours.