epidermal growth factor receptor expression of premalignant lesions of head and neck as predictor for neoplastic potential

Cancer has been defined as fundamental disorder of cellular growth control, which arises in some cells through changes in genes (DNA level, gene amplification, mutation and rearrangement) or their expression (RNA and protein level) and gives these cells a growth advantage in comparison to the surrounding cells.Many diagnostic and prognostic indicators have been used to predict the clinical course of squamous cells carcinoma of the head and neck. EGF -R gene is a sensitive factor in predicting the neoplastic potential dyspastic tissues.The aim of this study was to define changes in the EGFR expression of premalignant lesions of head and neck and compare this with expression ofEGF-R in normal head and neck tissues that might be of diagnostic or prognostic importance.First group: 20 biopsies obtained from patients with newly diagnosed premalignant lesions.Second group: 10 biopsies were obtained from patients with . malignant lesions from different sites of head and neck.Third group: 20 control biopsies were obtained from a systematic non-tulTIoral areas of head and neck.Using anti h-EGFR monoclonal antibody and a modification of the avidin-biotin immunoperoxidase method ”horseradish peroxid¬ase”.EGFR expressIOns were measured in all specimens under high power. Microscopy, we defined the membrane of the cell associated expression as positive staining of EGFR that gives dark brownish coloration.Immunostaining of dysplastic premalingnant epithelium revealed EGF-R expression in the epithelium of all premalignant samples.Also immunochemical analysis of normal mucosa (control) revealed minimal but detectable levels of membrane associated EGFR in all samples. EGFR expressions were high in adjacent area to SCCHN which is histologically normal appearing epithelium indicated that the development of elevated levels of EGFR may signal an early event in carcinogenesis in SCCI-IN.EGFR expression levels increased wth progression of dysplasia.So EGFR levels are linked to the degree of dysplasia and not some other features of aerodigestive tract.There were very high levels of EGFR in all malignant tissues and significantly more than that in premalignant.Over expreSSIOn of EGFR is found in the tumors, premalignant lesions and normal appeanng epithelium adjacent to tumors from head and neck cancer patients compared with controls.EG FR expression levels in premalignant lesions appear to be a sensitive factor in predicting the neoplastic potential of dysplastic tissues. This suggest that EGFR may serve as a biological markers to identify high risk groups and guide prophylactic therapy.