Correlation of EGFR and c-erbB-2 expression with histopathologic grading of mucoepidermoid carcinoma of salivary glands

Abstract

Mucoepidermoid carcinoma is the most common salivary gland malignancy which is classified into three histopathologic grades: low, intermediate and high grades. Because of the highly variable biologic potential of different histopathologic grades of the tumor, identification of the patientEs histopathologic status is of great importance in the treatment and determination of final prognosis. Materials and methods: This retrospective study included 46 slides and 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, their correlation and histopathologic grading were statistically analyzed by ANOVA. Nineteen samples of normal salivary gland tissue were also used as controls. Results: The means of EGFR and c-erbB-2 alone and mean of EGFR and c-erbB-2 together were 71%, 71%, and 71%, respectively. Statistically significant correlation was found between EGFR expression, mean of EGFR and c-erbB-2 expression together, 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 the histopathologic grading of salivary gland mucoepidermoid carcinoma and an increase in EGFR expression and the mean of EGFR and c-erbB-2 expression together; therefore, immunohistochemistry is a helpful technique for determination of the biologic behavior of salivary gland mucoepidermoid carcinoma and probably its prognosis.