Ezrin is Significantly Overexpressed in Luminal A, Luminal B, and HER2 Subtype Breast Cancer.

Ezrin, a membrane-linking protein, has been shown to play an important role in the carcinogenesis of infiltrating breast ductal carcinoma and its strong expression has been used to predict poor prognosis in patients with breast carcinoma. In this study, we compared ezrin protein distribution pattern in benign breast disease and breast cancer molecular subtypes and evaluated their association with clinicopathologic variables. A total of 376 breast cases (142 benign and 234 malignant cases) were studied. Immunohistochemical analysis for ezrin was performed and its expression was observed in terms of its distribution, intensity, and proportion of cells reactive for ezrin. Ezrin was expressed in all benign cases and 91.7% of malignant cases. Apical staining was positively associated with benign breast disease, whereas membranous and cytoplasmic staining were more frequently observed in malignant cases, specifically of hormone receptor-positive subtypes (luminal A and luminal B). Ezrin was significantly overexpressed in luminal A, luminal B, and HER2 subtypes. Reduced ezrin expression was significantly associated with triple-negative breast cancer molecular subtype. No significant association was demonstrated between ezrin expression and Her2 gene amplification, tumor grading, or staging.