NO EVIDENCE FOR C-ERBB-2 OVEREXPRESSION IN GASTRIC CARCINOGENESIS

Aims: Conflicting data on c-erbB-2 overexpression in gastric carcinoma s can be found in the literature with regard to overall prevalence, pr ognostic significance and the histological type according to Lauren. T he majority of these studies have focused on advanced gastric carcinom as whereas data on c-erbB-2 overexpression in early gastric carcinomas , especially of Caucasian origin, are relatively sparse, We therefore examined a series of Caucasian early gastric carcinomas to assess over all c-erbB-2 overexpression and to correlate c-erbB-2 overexpression, if any, with the type of growth pattern and the Lauren type. Methods a nd results: Forty-five paraffin-embedded gastrectomy specimens from ea rly carcinomas were examined for the presence of chronic active gastri tis. chronic atrophic gastritis, subtypes of intestinal metaplasia and dysplasia, The Lauren type and the type of growth pattern were reasse ssed for all early carcinomas, c-erbB-2 overexpression was assessed wi th monoclonal antibody 3B5 and polyclonal antibody A485. Complete abse nce of c-erbB-2 overexpression was observed in chronic active gastriti s, chronic atrophic gastritis, subtypes of intestinal metaplasia, and dysplasia, Moreover, c-erbB-2 overexpression was found absent in both intestinal-type (n=20) and diffuse-type early gastric carcinomas (n=25 ), irrespective of growth type. Conclusions: c-erbB-2 overexpression d oes not play a role in the progression from normal to neoplastic gastr ic mucosa and should be considered as a late event in gastric carcinog enesis. Moreover, c-erbB-2 overexpression does not discriminate betwee n intestinal and diffuse type early gastric carcinomas of Caucasian or igin. Finally, it appears that mechanisms other than c-erbB-2 overexpr ession underlie the reported differences in biological behaviour of ea rly gastric carcinomas with different types of growth pattern.