Gastric carcinoma exhibits distinct types of cell differentiation: an immunohistochemical study of trefoil peptides (TFF1 and TFF2) and mucins (MUC1,MUC2, MUC5AC, and MUC6)

The expression of trefoil peptides (TFF1 and TFF2) and mucins (MUC1, MUC2, MUC5AC, and MUC6) has previously been described in gastric polyps. In the p resent study, the expression profile of these trefoil peptides and mucins w as characterized in 96 gastric carcinomas, in an attempt to further the und erstanding of the histogenesis and cell differentiation of gastric carcinom a. Taking together the co-expression of trefoil peptides and mucins, three phenotypes were defined: complete gastric, incomplete gastric, and non-gast ric phenotype, Gastric differentiation (complete and incomplete) was observ ed in 30 out of 33 (90.9%) diffuse carcinomas and in 38 out of 53 (71.7%) i ntestinal carcinomas. Non-gastric differentiation was observed in only thre e (9.1%) diffuse carcinomas and in 15 (28.3%) intestinal carcinomas, The ph enotypes observed in intestinal carcinomas were similar to those previously observed in adenomatous polyps, whereas most diffuse carcinomas mimicked t he phenotype of hyperplastic polyps, The percentage of cases displaying a n on-gastric phenotype was higher, though not significantly, in tumours that had invaded the gastric wall than in T1 tumours, regardless of histotype, I t is concluded that gastric-type differentiation is retained in the majorit y of gastric carcinomas, being more prominent in diffuse than in intestinal carcinomas, and in early than in advanced carcinomas. Copyright (C) 2000 J ohn Wiley & Sons, Ltd.