| Abstract: |
There is much clinical and experimental evidence that colon carcinoma in humans evolves through a series of preneoplastic stages. Preneoplastic colonic cells have been characterized in normal-appearing epithelium of (flat mucosae) from patients genetically at risk to develop colon cancer. These cells differ from normal colonic epithelial cells by a delay in terminal differentiation which leads to an enlargement of the zone of dividing cells within the colonic crypt, a test-tube-like hollow cylinder roughly 50-60 cells deep (1,2). These patients include those with familial polyposis or Gardner's syndrome and those without polyposis, but with a family history of first-degree relatives with colon cancer. Such crypts with extended proliferative zones are not only characteristic of patients genetically predisposed to develop colon cancer, but are found in patients without any known syndrome who have developed a carcinoma (3). The biopsies were taken at least 4 cm from the tumor, suggesting an area of altered epithelial cells had arisen within the colon and that the carcinoma arose from some of these precursor cells. Supporting this interpretation is the finding that such abnormal crypts predate the appearance of adenomas and carcinomas in the dimethylhydrazine-induced model of colon carcinoma in CF, mice (3). © 1985 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted. |
