Distribution of two tumor-associated antigens in gastric lesions as detected by two monoclonal antibodies on tissue sections.

Two monoclonal antibodies antitumor-associated antigens, B1.1 and B72.3, have been used with the immunoperoxidase technique on tissue sections to study gastric carcinomas, dysplasia, intestinal metaplasia, and adenomas. B1.1 reacts with carcinoembryonic antigen (CEA); B72.3 reacts with a 220-400 kd glycoprotein present in colon, breast, and other carcinomas. CEA was found in 89% (34 of 38) and B72.3 antigen in 92% (35 of 38) of carcinomas. In half of these more than 50% of tumor cells were positive. The normal epithelium was usually negative or sporadically positive in a few cells. In dysplastic areas and adenomas the number of cells that were positive for the two antigens was greater than in normal epithelium and smaller than in carcinomas. In intestinal metaplasia B72.3 antigen was almost always present, whereas CEA was sometimes undetectable. Both the antigens proved to be good markers of neoplastic versus normal cells. The presence of B72.3 antigen in addition to CEA in dysplasia, adenomas, and intestinal metaplasia adds further evidence of their close relationship with gastric cancer.