IMMUNOHISTOCHEMICAL DETECTION OF CARCINOEMBRYONIC ANTIGEN (CEA) WITH ANTI-CEA MONOCLONAL-ANTIBODIES IN CONVENTIONAL TISSUE-SECTIONS

We assayed 448 malignant tumors (187 of colorectal and 261 of non-colo rectal origin), 27 colorectal micrometastases to different organs and tissues, 97 ulcerative colitis, 40 tubular adenomas, 31 hyperplastic p olyps and 162 normal tissue sections for CEA expression by immunohisto chemistry, using D-14 anti-CEA monoclonal antibody (MAb). D-14 always react with colorectal carcinomas, frequently with other tumors of gast rointestinal origin (esophagus, stomach and pancreas) and less frequen tly with tumors of non-gastrointestinal origin (11%). D-14 did not sta in any of 162 normal tissues, including normal colon and rectum. Addit ionally, the reaction of D-14 and three other commercially available a nti-CEA MAb's (SP-625, ZCEA1, CEJ0625) were analyzed in 97 colorectal carcinomas, 154 non-colorectal carcinomas and 41 normal colorectal tis sues. D-14, CEJ065 and SP-625 reacted with essentially every colorecta l carcinoma. In contrast, ZCEA1 was the least reactive, and 14 tumor s amples showed no reactivity to this MAb. The number of esophageal, lun g and breast carcinomas stained was similar for ZCEA1 and D-14 MAb but lower than in the group stained with the SP-625 and CEJ065 MAb's. Onl y D-14 MAb was consistently negative in normal colorectal tissues. In 27 cases, clusters of atypical cells (possible colorectal micrometasta ses) could be identified with D-14 MAb. A good correlation was found b etween the CEA expression and dysplasia in tubular adenomas and ulcera tive colitis. This suggests that CEA assessment might be an additional factor in the evaluation of malignant potential of these lesions