Immunohistochemical correlation of epidermal growth factor receptor and c-erbB-2 with histopathologic grading of mucoepidermoid carcinoma

Abstract

Objective: Mucoepidermoid carcinoma is the most common salivary gland malignancy with highly variable biologic potential that correlates with the histopathologic grade of the tumor. Therefore, identification of the histopathologic grade of the mucoepidermoid carcinoma is very important in the treatment and determination of the final prognosis. The present study was performed to survey immunohistochemically Epidermal Growth Factor ReceptorEGFR and c-erbB-2 expression in different grades of mucoepidermoid carcinoma.

Materials and methods: This retrospective study included 46 formalin-fixed, paraffin-embedded blocks of mucoepidermoid carcinoma. Based on histopathologic parameters, samples were classified into three grades. Then new sections were made and stained by immunohistochemistry (IHC) method for EGFR and c-erbB-2. Finally, EGFR and c-erbB-2 expression and their correlation with histopathologic grading were statistically analyzed by ANOVA. Nineteen samples of normal salivary gland tissue were also chosen as control group.

Results: The means of EGFR and c-erbB-2 were 71%, 71%, respectively. Statistically significant correlation was found between EGFR expression and histopathologic grading of mucoepidermoid carcinoma of salivary glands (P < 0.001). There was no statistically significant correlation between histopathologic grading of salivary gland mucoepidermoid carcinoma and c-erbB-2 expression (P = 0.60).

Conclusion: There is a parallelism between an increase in EGFR expression and increase in the histopathologic grading of salivary gland mucoepidermoid carcinoma. Therefore, the biologic behavior of salivary gland mucoepidermoid carcinoma can be determined by EGFR expression and it is a useful technique for determination of tumor grades and probably their prognosis.