Morphologic Changes,Mucin Secretion,Carcinoembryonic Antigen (Cea) and Peanut Lectin Reactivity in Colonic Mucosa of Patients at High Risk for Colorectal Cancer

Abstract

We studied 393 endoscopic colonic biopsies from 72 patients, classified in different groups after assessment of their risk factors, using: histologic, histochemical and immunohistochemical techniques (CEA-PAP and PNA-Px). In high risk patients (Groups A and B) the most relevant modifications were dysplasia with hyposecretion and hyperplasia with sialomucin secretion (TR-type change); in Group A 31 adenomas and 19 hyperplastic polyps also were found. A premalignant nature of dysplasia and predysplastic significance of TR change were suggested: 1) by finding the same alterations in mucosa of Group E (colectomized patients for carcinoma at after 1 year); 2) by increasing expression of CEA and PNA-Px ligands; 3) by their absence in Group D (normal controls). Hyperplastic polyps were confirmed not to be premalignant lesions, but since they had peculiar characteristics (increased CEA and PNA-Px positivity, association with adenomas) it does not seem justified to regard them as lesions unrelated to colorectal cancer, especially when associated with other risk factors. CEA and PNA-Px reactivity correlated well with the risk evaluation and with morphohistochemical changes in the mucosa; the reactivity significantly increased from normal mucosa to dysplasia.