Expression and clinical significance of the receptors of the EGF family in oral squamous cell carcinomas

Objective: To examine the immunohistochemical expression of four members of the type 1 growth factor receptor family in oral squamous cell carcinomas (OSCCs) and to correlate with clinical outcomes. Materials and methods: Sixty OSCCs from a patient cohort in Sri Lanka were included in the study. Five sections from each carcinoma were immunostained with antibodies to epidermal growth factor receptor (EGFR)/c-erbB-1, c-erbB-2/HER-2/neu, c-erbB-3/HER-3 and c-erbB-4/HER-4. Two clones were used to stain for c-erbB-2/HER-2/neu. Semiquantitative analysis of immunoreactivity was carried out by scoring the intensity of expression and proportions of positively stained cells. A logistic regression analysis was performed to examine positive expression against overall survival. Results: There was heterogenous expression of the four receptors, positivity ranging from 26% to 60%. Co-expression of all four markers was observed only in 1–3% of the tumours. Both membranous and cytoplasmic expressions were observed, EGFR showing predominantly membranous expression and c-erbB-2 showing only cytoplasmic staining. In logistic regression analysis, none of the growth factor receptors were significantly predictive of overall survival. Conclusion: Type 1 growth factor receptors are highly expressed in oral carcinomas, EGFR being the predominant marker.