IMMUNOEXPRESSION OF C-ERBB-2 AND P53 IN BENIGN AND MALIGNANT SALIVARYNEOPLASMS WITH MYOEPITHELIAL DIFFERENTIATION

Aim-To evaluate whether the immuno-expression of c-erbB-2 and p53 is i nvolved in the pathogenesis and progression of salivary tumours with m yoepithelial differentiation. Methods-233 tumours from 211 patients we re studied. These included 76 primary and 24 recurrent adenocarcinomas (polymorphous low grade adenocarcinoma, 13; epithelial-myoepithelial carcinoma, 19; adenoid cystic carcinoma, 56; and basal cell adenocarci noma, 12) and 133 pleomorphic adenomas and myoepitheliomas, 96 being p rimary and the remaining recurrent tumours. All cases were formalin fi xed and paraffin wax embedded. A StrepABC peroxidase method and polycl onal c-erbB-2 and p53 specific antisera were used. Results-Cell membra ne staining of c-erbB-2 was not found in any benign or malignant tumou r. There was p53 protein accumulation in one primary and one recurrent pleomorphic adenoma and in 10 adenocarcinomas (polymorphous low grade adenocarcinoma, one; epithelial-myoepithelial carcinoma, one; adenoid cystic carcinoma, five; and basal cell adenocarcinoma, three), three of them being recurrences. Conclusions-The c-erbB-2 and p53 proteins a re not involved in the pathogenesis of pleomorphic adenoma and myoepit helioma and do not constitute biomarkers in assessing the risk of recu rrence. c-erbB-2 is not involved in the genesis of low grade salivary neoplasia with myoepithelial differentiation. The percentage of this t ype of neoplasia with p53 accumulation is low (10%) and does not appea r to be related to tumour recurrence.