Differences in p53 and cadherin-catenin complex expression between histological subtypes in diffusely infiltrating gastric carcinoma.

The aim of this study was to elucidate possible clinicopathological differences between diffusely infiltrating gastric carcinoma of 'pure type' (poorly differentiated carcinoma without any glandular component) and 'mixed type' (coexistence of poorly differentiated carcinoma and intramucosal glandular component). The clinicopathological features and immunohistochemical expression of p53 and intercellular adhesion molecules (E-cadherin and alpha-, beta- and gamma-catenins) were compared between the patients with pure (n=59) and mixed (n=56) types of diffusely infiltrating gastric carcinoma. Intestinal metaplasia (P < 0.01), prominent lymphatic permeation (P < 0.001) and lymph node metastasis (P < 0.05) were more frequently observed in mixed type than in pure type, while survival probability did not differ between the two groups. The frequency of p53 over-expression was higher in mixed type (56%) than in pure-type (19%) (P < 0.001). In mixed type, p53 expression was not different between glandular and poorly differentiated components. By contrast, the expression of adhesion molecules was more frequently preserved in glandular components than in poorly differentiated components. These two subtypes seem to be different in nature and biological behaviour. The preservation of adhesion molecules in mixed type may be associated with higher incidence of lymphatic permeation and lymph node metastasis.