Correlation between androgen receptor expression and surrogate molecular subtypes in invasive breast carcinoma

Objective: To investigate androgen receptor(AR)expression in invasive breast carcinoma and the correlation with surrogate molecular breast carcinoma subtypes. Methods: Immunohistochemical staining of AR and other biomarkers was performed in a cohort of 870 cases of primary invasive breast carcinomas collected from August to December, 2016. The association of AR expression with different histological and surrogate molecular subtypes was analyzed. Results: The positive expression rate of AR in the immunohistochemistry-based surrogate subtypes was 96.3%(207/215) for Luminal A, 89.8%(378/421) for Luminal B, 82.4%(75/91) for HER2 overexpression and 37.1%(53/143) for triple negative breast carcinoma, with significant differences among the four groups (P<0.01). AR correlated positively with the expression of ER(P<0.01), PR(P<0.01), HER2(P=0.007), GATA3(P<0.01), GCDFP15(P<0.01)and mammaglobin(P<0.01), while negatively with the expression of Ki-67(P<0.01), CK5/6(P<0.01)and CK14(P<0.01). Conclusions: AR exhibits a high expression in invasive breast carcinoma, which is mainly correlated with ER-positive breast carcinoma. Regardless of the relatively low expression rate, AR is a potential therapeutic target in triple negative breast carcinoma.