CEA in colonic adenocarcinomas and precancerous lesions. An immunohistochemical study with a novel monoclonal antibody.
Using a new anti-CEA (CB-CEA-1) murine monoclonal antibody, the expression of carcinoembryonic antigen (CEA) was studied in normal, premalignant and malignant human adult tissues with particular emphasis on colorectal mucosa. The CB-CEA-1 epitope was poorly expressed in normal adult tissues but was consistently found in colon cancers and adenomas in distinctive immunohistochemical patterns. Some apical staining was found with CB-CEA-1 in cells of normal colon mucosa whereas colon adenocarcinomas had a predominantly cytoplasmic staining pattern. Colonic adenomas presented a varied staining pattern. Some showed apical staining, others a CEA distribution pattern similar to that of adenocarcinomas, particularly those with a villous component. Our findings indicate a differential expression of CB-CEA-1 in adenoma cells in relation to their potential for malignant transformation. The possible usefulness of this Mab defined epitope for diagnostic and therapeutic purposes is indicated.