PS2 PROTEIN EXPRESSION IN GASTRIC-CARCINOMA - AN IMMUNOHISTOCHEMICAL AND IMMUNORADIOMETRIC STUDY

The aim of this study was to examine the prevalence of pS2 expression in gastric carcinoma and to determine its prognostic significance. We analysed pS2 protein expression in 50 gastric carcinomas and respectiv e adjacent mucosas by immunohistochemistry and immunoradiometric assay (IRMA). pS2 was consistently expressed in superficial and foveolar ep ithelium of non-neoplastic mucosa and in 66.0% of the carcinomas. pS2 immunoreactivity was significantly higher in diffuse than in intestina l carcinomas, and in those cases with nodal metastases than in those w ithout. No correlation was found between pS2 immunostaining and gender , age, staging, depth of wall penetration, venous invasion, ploidy and S-phase fraction. The mean levels of pS2 (IRMA) were significantly lo wer in gastric carcinomas than in non-neoplastic mucosas, and were not correlated with any of the aforementioned clinicopathological feature s. The survival of patients with pS2-positive tumours was not signific antly different from that of patients with pS2-negative tumours. We co nclude that pS2 expression, which can be used as a marker of gastric-t ype differentiation, is associated with gastric carcinoma of diffuse t ype. The lack of correlation between pS2 expression and most features of tumour aggressiveness and patients' survival precludes its use as a prognostic tool in gastric carcinoma. Copyright (C) 1996 Elsevier Sci ence Ltd