Expression of epidermal growth factor receptor in oral cancer

Objectives:With ongoing efforts to target the epidermal growth factor receptor (EGFR)-mediated tumor growth in the treatment of selected human malignancies, there is a need to determine the expression levels of EGFR in oral squamous cell carcinomas (SCC). Methods:Sixty archived formalin fixed and paraffin embedded oral squamous cell carcinomas specimens from the patients who previously underwent biopsy /resection were retrieved for this study.Twenty normal oral mucosa specimens were used for control group. For each case hematoxylin and eosin staining for one tissue section was performed for a histological review and to obtain a representative number of SCCs showing a variety of histological differentiation. The rest of the sections were subjected to EGFR-immuno-peroxidase staining to evaluate EGFR expression. In comparison with the staining of normal oral mucosa specimens, each SCC lesion was evaluated by light microscope with estimation of the extent of immunoreactivity (population of the stained tumor cells ) and the staining intensity. Results: Normal oral mucosa showed minimal staining of the basal and suprabasal layers for EGFR, whereas 90% of tumor lesions showed moderate to strong staining for EGFR in a diffuse pattern. The EGFR immunostaining was linear and detected around the tumor cells membrane. Correlation was strong between presence of EGFR and differentiation; the EGFR-positive cells were differentiated, whereas poorly differentiated tumors exhibited less intense staining. Conclusions: The majority of SCCs were stained positively for EGFR, and in a big percentage the staining was quite intense. The EGFR overexpression may contribute to a more aggressive phenotype resulting in a greater risk of death from the disease.On the basis of the already proven antitumoral effect of agents acting as EGFR inhibitors (gefitinib), it is suggested that patients with SCCs might benefit from these agents, especially when surgery has failed or in those with recurrent or metastatic disease.