Triple-Negative Breast Cancer: The Progress of Targeted Therapies and Future Tendencies

Abstract

Triple-negative breast cancer (TNBC) is characterized by a lack of expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) and unfortunately is not associated with good prognosis. Treatment of breast cancer mainly depends on chemotherapy, due to the lack of specifically approved targeted therapies for TNBC. It is of paramount importance to find new therapeutic approaches, as resistance to chemotherapy frequently occurs. Herein, we present clinical studies published within the last five years, in order to reveal possible targeted therapies against TNBC. We aimed to discuss factors against TNBC, such as tyrosine kinase inhibitors, anti-androgens, poly ADP-ribose polymerase-1 (PARP-1) inhibitors, anti-angiogenic factors, immune checkpoints and histone deacetylase inhibitors (HDACI). Furthermore, the PI3K/AKT/mTOR pathway seems to be a promising field for the development of new anti-TNBC targeted therapies. Data from 18 clinical trials with patients suffering from TNBC were summarized and presented descriptively.