The Potential of Hormonal Therapies for Treatment of Triple-Negative Breast Cancer

SIMPLE SUMMARY: The presence of estrogen receptor beta, the androgen receptor, and the glucocorticoid receptor on triple-negative breast cancer cells has opened the possibility for the development of new treatment approaches against this disease. This review summarizes the current knowledge and development regarding the presence and function of these receptors in triple-negative breast cancer. Key data from current and previous clinical trials targeting these receptors are also described in detail. ABSTRACT: Triple-negative breast cancer (TNBC) is considered one of the most aggressive forms of breast cancer with poor survival rates compared to other breast cancer subtypes. TNBC is characterized by the absence of the estrogen receptor alpha, progesterone receptor, and the human epidermal growth factor receptor 2, limiting those viable treatment options available to patients with other breast cancer subtypes. Furthermore, due to the particularly high heterogeneity of TNBC, conventional treatments such as chemotherapy are not universally effective, leading to drug resistance and intolerable side effects. Thus, there is a pressing need to discover new therapies beneficial to TNBC patients. This review highlights current findings regarding the roles of three steroid hormone receptors, estrogen receptor beta, the androgen receptor, and the glucocorticoid receptor, in the progression of TNBC. In addition, we discussed several ongoing and completed clinical trials targeting these hormone receptors in TNBC patients.