Usefulness of proliferative activity, DNA ploidy pattern and p53 products as diagnostic adjuncts in colorectal adenomas and intramucosal carcinomas

Although numerous studies have assessed the biologic parameters of tumors, measurement of these parameters has had, to date, little impact on histolog ic diagnosis. Furthermore, analysis of a single parameter is insufficient t o evaluate tumor malignant potential. In the present study, cell proliferat ion, DNA ploidy and p53 product were analyzed to objectify the tumor malign ant potential in colorectal adenomas and intramucosal carcinomas. Sixty-one adenomas and 49 intramucosal carcinomas were studied using immunohistochem ical analysis of Ki-67 and p53, silver-staining nucleolar organizer region (AgNOR) stain and DNA ploidy in fresh samples. Intramucosal carcinoma exhib ited a greater Ki-67-positive rate and AgNOR count than the adenomas, altho ugh these parameters varied widely among samples. The incidence of aneuploi dy and p53 overexpression in colorectal intramucosal carcinomas was signifi cantly higher than in colorectal adenomas. These results indicate that DNA aneuploidy and p53 accumulation are the most reliable parameters for distin guishing benign and malignant lesions.