Early precancerous modifications in the mucus of human and rat distal colon: a comparative immunohistologic study.

The M1 antigens, associated with gastric fucomucin, the early oncofetal precancerous marker for the distal colon, were studied using the immunoperoxidase method in the distal colon. We compared human tumoral mucosa with that of rats during DMH-induced carcinogenesis. In both cases we examined histologically normal mucosa, mucinous hyperplasia, glands with serrated epithelium and hypermature goblet cells like those observed in human hyperplastic polyps, dysplasia, and transitional mucosa. We were able to assess similarities between these rat and human mucosae in terms of the tissue and cell location of these M1 antigens as well as the frequency of occurrence in the different comparative lesions. Thus, we demonstrated that such similarities can be observed not only at a histologic level, but also on a molecular level. The presence of M1 antigens in the human distal colon is comparable to mucous modifications induced by a chemical carcinogen, as observed during DMH-induced carcinogenesis in the rat.