CDW75 ANTIGEN EXPRESSION IN HUMAN GASTRIC-CARCINOMA AND ADJACENT MUCOSA

Background. The amount of sialic acid correlates with the invasiveness and metastasizing potential of several human tumors. The CDw75 epitop e is a sialylated carbohydrate determinant generated by the beta-galac tosyl a2,6-sialyltransferase, which can be viewed as a target for iden tifying biologically aggressive tumors. Methods. The authors performed an immunohistochemical study of CDw75 epitope expression in 87 cases of gastric carcinoma and adjacent mucosa and 331 metastases (329 lymph node metastases and 2 liver metastases) with the monoclonal antibody HH2. Results. Normal-appearing mucosa, foci of intestinal metaplasia, and foveolar hyperplasia, adjacent to the carcinomas, were mainly noni mmunoreactive. Only a few parietal cells of the body mucosa were stain ed with HH2. Two of 12 cases with dysplasia showed CDw75 antigen expre ssion in dysplastic glands. Forty-one cases (47.1%) were immunoreactiv e for CDw75 antigen in the primary tumors or metastases. A very close relationship was found between the expression of the antigen in primar y tumors and their respective metastases. The expression of the antige n was correlated with an infiltrative growth pattern, lymphatic invasi veness, and aneuploidy. All but two immunoreactive cases had lymph nod e metastases or lymphatic permeation. No relationship was found betwee n CDw75 antigen expression and the morphologic types of gastric carcin oma, amount of lymphoid infiltrate, vascular invasion, and penetration of the gastric wall. Conclusions. The authors conclude that Cdw75 ant igen expression can be used as a marker of malignant transformation of gastric epithelium and is a good indicator of the biologic aggressive ness of gastric carcinoma.