Expression of androgen receptors and inhibin/activin α and βA subunits in breast apocrine lesions

The importance of androgens and their receptors inhibin and activin remains unknown for mammary epithelial cells. We investigated the role of these hormones in breast apocrine lesions (BAL) using immunohistochemistry to study androgen receptors (AR) and the inhibin/activin α and βA subunits. Forty-two cases of BAL were evaluated, including 22 cases of fibrocystic disease (FCD) showing prominent apocrine changes, 10 intraductal papillomas with extensive apocrine metaplasia, 5 cases of apocrine carcinoma in situ (CIS), and 5 cases of apocrine carcinoma. Fifty non-apocrine lesions were included as controls: 20 cases of FCD, 5 cases of DCIS, and 25 cases of invasive ductal carcinoma. AR was more frequently expressed in BAL than in non-apocrine lesions (p=0.001). AR expression was not related to tumor progression. AR showed a significant positive correlation with βA subunits (r=0.832, p<0.001), and an inverse correlation with α subunits (r=-0.233). The α and βA subunits demonstrated a significant inverse correlation with each other (r=-0.271, p=0.0048). As the expression of the α and βA subunits reflects inhibin and activin A, respectively, AR and activin A may be implicated in apocrine morphogenesis, but not in tumor progression.