Expression of c-erb B-2 oncoprotein in cancer of the larynx in relation to invasion of the cartilagenous framework and prognosis.

Oncogenes are important cellular genes that in general promote in the normal growth regulatory pathways. The human c-erb B-2 proto-oncogene (HER-2 or neu) encodes a 185 kDa transmembrane putative growth factor receptor of the tyrosine kinase family. This oncogene has been shown to be over expressed and/or amplified in primary carcinoma of the breast, ovary, pancreas and salivary glands. This study was conducted to evaluate a possible link between amplification of c-erb B-2 oncoprotein and cartilage invasion in laryngeal carcinoma. In addition, data concerning overexpression were compared to other clinicopathological parameters as well as clinical outcomes. In all, 34 patients with squamous cell carcinoma of the larynx were studied prospectively. Total laryngectomy specimens were sliced in horizontal sections at 4- to 5-mm intervals. Specimens were preserved in 10% formalin, and histopathological examinations were carried out after embedding tissues in paraffin sections and then staining them with hematoxylin and eosin. Detection of c-erb B-2 oncoprotein overexpression was carried out with a polyclonal antibody and an avidin-biotin kit. The level of c-erb B-2 overexpression was determined using the Quantimet 520 Leica image analyzing system. However, no significant correlation was found between cartilage invasion and clinicopathological parameters and prognosis. Overexpression of c-erb B-2 attained no significant correlation with clinicopathological parameters. In contrast, the correlation of c-erb B-2 overexpression and cartilage invasion was statistically significant (P = 0.034). In general, overexpression of c-erb B-2 oncoprotein was related to the more aggressive tumors with high capability of invading laryngeal cartilages. Patients with +ve c-erb B-2 oncogene had a poor prognosis but this was not statistically significant when compared to the clinical outcomes of patients with the -ve c-erb B-2 oncogene.