Prognostic Value of Androgen Receptor Expression in Breast Cancer Cells

Abstract

The review discusses the importance of the expression of androgen receptor (AR) in patients with breast cancer (BC). AR is expressed in normal tissues of the breast and in most of the molecular sub-types of BC. AR are located with estrogen (ER) and progesterone (PR) receptors in epithelial cells, but not in the stroma of breast. Up to this date there is no common opinion about the role of the lev-el of androgens and their metabolites in biological fluids samples in the development of BC. Hy-pothesis, that androgens are directly involved in BC cancerogenesis, is based on the presence of AR in the majority of breast carcinomas. AR expression was higher in ER positive subtypes (90% Lu-minal A, 70-90% Luminal B and lower in ER negative subtypes (60% HER2, 10-50% triple- nega-tive cancer. The opinion prevails, that patients with tumours positive to АR, are characterised by a better prognosis than negative to AR. The most aggressive type of BC is triple-negative breast can-cer (TNBC), characterized by high proliferative activity and doesn’t respond to the hormonal thera-py. Оne of the aims of the present study is to explore the clinical significance of AR and provide evidence for AR-directed treatment in TNBC. In recent years, the issue of targeted therapy for AR expression has been actively discussed. In a study by Gucalp et al (2013), the efficacy of bicalutam-ide in patients with AR + THNBC with AR expression ≥ 10%, ER-, PR- was determined. Twenty-six patients received 150 mg of bicalutamide daily, and 19% patients had improvements in the gen-eral condition. In a preclinical study of the effect of Enzalutamide and Bicalutamide in ER + (AR +) BC, it has been shown that Enzalutamide is more effective than Tamoxifen because it reduces proliferation in both ER + BC and ER- BC patients.