PKC α and ER β Are Associated with Triple-Negative Breast Cancers in African American and Caucasian Patients

Abstract

Although the incidence of breast cancer in the United States is higher in Caucasian women compared with African American women, African-American patients have more aggressive disease as characterized by a higher percentage of triple-negative breast cancers (TNBCs), high-grade tumors, and a higher mortality rate. PKC α is a biomarker associated with endocrine resistance and poor prognosis and ER β is emerging as a protective biomarker. Immunohistochemical analysis of ER β and PKC α expression was performed on 198 formalin-fixed paraffin-embedded primary infiltrating ductal carcinomas from 105 African-American and 93 Caucasian patients. PKC α is positively correlated with TNBC in patients of both races and with high tumor grade in African-American patients. Patients with TNBC express less nuclear ER β compared with all other subtypes. We find no difference in frequency or intensity of PKC α or ER β expression between African-American and Caucasian patients. PKC α and ER β are discussed as potential therapeutic targets for the treatment of patients with TNBC.