Over-expression of p53 and c-erbB-2 oncoproteins in laryngeal carcinoma.

Abstract

An immunohistochemical analysis of over-expression of p53 and c-erbB-2 proteins was performed on 27 biopsies of laryngeal carcinoma. The aim of this study was to investigate whether there is a correlation between over-expression of these proteins and the clinicopathological features of the tumor and to reveal any possible prognostic value. Paraffin sections of laryngeal carcinoma were studied using immunohistochemical staining with mouse and rabbit monoclonal antibodies, respectively, for p53 and c-erbB-2 proteins. The positive controls were paraffin-embedded specimens from ten breast carcinomas previously shown to express these proteins. Ten benign laryngeal nodules were immunohistochemically stained as negative controls. Samples from 74% of 27 patients with laryngeal carcinomas demonstrated positive nuclear and cytoplasmic (or membranous) staining for p53 protein and 48% were positive for c-erbB-2 protein. In the present study, while there was a slight difference in the frequency of p53 over-expression among stage I-II and stage III-IV tumors, there was no difference in the frequency of p53 over-expression among primary and recurrent tumors. There was no statistically significant correlation between over-expression of the p53 and c-erbB-2 proteins and the age of the patients, tumor site, tumor grade, clinical stage, histopathological grading of the tumor, alcohol consumption, and clinical outcome. There was a statistically significant correlation between immunostaining of p53 and c-erbB-2 proteins (P = 0.037). While it was found that over-expression of p53 was significantly associated with the presence of lymph node metastasis (P = 0.006), there was no association between the expression of c-erbB-2 and lymph node status. The data demonstrated increased expression of p53 and c-erbB-2 proteins, presumed to be mutant, in laryngeal carcinomas. Hence, we conclude that p53 and c-erbB-2 over-expression as detected by immunohistochemical staining in larynx carcinomas is not predictive of poor survival or disease-free survival.