Expression of androgen receptors in triple negative breast carcinomas

Abstract

Triple negative breast cancer (TNBC) consists of a group of tumors with poor prognosis, owing to aggressive tumor biology and lack of targeted therapy. The aim of this study was to assess the immunostaining for androgen receptors (ARs) in the group of TNBC, in addition to basal-like (BL) immunophenotype, BL morphology and conventional clinicopathological factors and to demonstrate its prognostic relevance in this group of tumors. The study included 83 patients. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER2, CK5/6, CK14, EGFR, Ki-67 and AR. Of the 83 TNBC samples, 32.5% showed positive immunostaining for AR, 66.3% had BL immunophenotype, and 48.2% had BL morphology. Positive AR immunostaining was inversely correlated with higher clinical stage, higher mitotic score, higher histological grade and higher proliferation index measured by Ki-67. Significantly more AR negative tumors were observed among the tumors with BL immunophenotype and BL morphology. There was no significant association between positive AR immunostaining and disease free survival or overall survival. More than one third of TNBC were AR-positive, and this represents a potential opportunity for novel targeted treatment in the group of breast tumors for which therapeutic options are currently limited.