IMMUNOHISTOCHEMICAL ANALYSIS OF INTERCELLULAR-ADHESION MOLECULE-1 EXPRESSION IN HUMAN GASTRIC ADENOMA AND ADENOCARCINOMA

In this study, we examined the distribution of intercellular adhesion molecule-1 (ICAM-1) in gastric adenomas and carcinomas immunohistochem ically at the light and electron microscopic levels. ICAM-1 was expres sed on tumour cells in 12 of 28 gastric carcinomas and in 3 of 11 aden omas but not on most normal gastric epithelial cells. ICAM-1 was local ized on luminal sites of neoplastic glands in adenomas and in intestin al-type carcinomas, and rarely on the surface of tumour cells of diffu se carcinomas. Expression of ICAM-1 on the tumour cells was more frequ ent in intestinal-type than diffuse carcinomas (P<0.005). At the ultra structural level, ICAM-1 was present prominently on the apical membran e and weakly on the lateral surface of the tumour cells of the intesti nal-type carcinoma and also localized on the perinuclear membrane and the membrane of the endoplasmic reticulum of cancer cells. There was n o significant association between ICAM-1 expression and HLA antigen ex pression or the number of infiltrating lymphocyte subsets. These resul ts may implicate the synthesis of ICAM-1 by gastric cancer cells, but the expression is infrequent and may not be sufficient for host immune surveillance of the tumour cell.