IMMUNOHISTOCHEMICAL STAINING PROPERTIES OF EGFR IN SQUAMOUS CELL CARCINOMA OF LARYNX

Sections of paraffin blocks of 35 Squamous Cell Carcinoma (SCC) cases were stained by Epidermal Growth Factor Receptor (EGFR) immunohistochemically. Their staining properties and relation to differentiation were assessed. Twenty two of the cases were well differentiated and 13 of them were moderately or poorly differentiated. A case was accepted as positive if 5% or more of the tumoral area stained positively. Twenty three (65.7%) of the cases were evaluated as positive. Normal laryngeal epithelium of 21 patients were also assessed and positivity was observed in 11 (52.4%) of them. Considering EGFR positivity, there was no difference between normal larynx epithelium and tumor tissue, but a higher proportion of positivity was observed in well differentiated SCC than moderately- poorly differentiated SCC (P=0.032). According to previous reports, there was no association between tumor differentiation and EGFR expression, but some other papers advocate an association between EGFR expression and poor differentiation. This disagreement in literature and the results of our study reveal the need of researches in larger series to solve this disconcordance.