EPSTEIN-BARR-VIRUS IN GASTRIC-CARCINOMA

Epstein-Barr virus (EBV) is known to be related to lymphoid tumors and some types of epithelial tumors, including lymphoepithelioma-like gas tric carcinoma with marked lymphocytic stroma. In this study, prevalen ce of EBV involvement in gastric cancer, and characteristics of tumors with such involvement, were investigated by EBV-encoded RNA 1 in situ hybridization applied to paraffin sections, including the tumor and a djacent gastric tissue, from 999 gastric carcinomas observed in 9 70 c onsecutive cases from a large Japanese hospital. EBV involvement occur red in 69 percent of lesions, a significantly lower proportion than ha s been observed in a North American series. Involvement was significan tly more frequent among males, in tumors in the upper part of the stom ach, and in adenocarcinomas of the moderately differentiated tubular a nd poorly differentiated solid or medullary types. Almost all carcinom as with marked lymphoid stroma were EBV-positive. Positive lesions wer e characterized by the presence of uniform hybridized signals in almos t all carcinoma cells and by their absence from adjacent non-neoplasti c tissue.