Hormone receptors in breast cancer

Abstract

Steroid hormone receptors are critical for the growth and development of breast tissue as well as of breast cancer. The importance of the role estrogens in breast cancer has been delineated for more than 100 years. The analysis of its expression has been used not only to classify breast cancers but also for treating patients. The expression of ER and PR in tumors is associated with better prognosis and sensitivity to endocrine therapy. In this chapter we discuss the role of these receptors in addition to androgen receptor (AR) in breast cancer. A brief overview of the structure and function of these receptors and methods to detect their presence in breast cancer is presented. This includes criteria for scoring positivity and national and international guidelines associated with the scoring. Lastly, data regarding the use of expression of AR as therapeutic target, particularly in triple negative cancers, is presented.