Abstract
Triple-negative breast cancer (TNBC) is a very aggressive and heterogeneous subcategory of breast cancer characterized by the lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). TNBC accounts for approximately 15-20% of all breast cancer cases and mostly affects the younger female population, with the majority being from African and Hispanic lineages. Up to now, TNBC has been handled by a few lines of options, mainly chemotherapy, which alone leads to less-than-optimal outcomes in the absence of hormonal or HER2-targeted therapies. In recent years, important steps forward in the elucidation of the molecular and genetic characteristics of TNBC have been achieved, including the identification of new therapeutic targets. This review discusses several key emerging therapeutic targets, including but not limited to immune checkpoint inhibitors (ICIs), poly (ADP-ribose) polymerase (PARP) inhibitors, androgen receptor (AR) inhibitors, PI3K/AKT/mTOR pathway inhibitors, and agents targeting DNA damage repair mechanisms. A number of new therapeutic options epitomizing this paradigm shift in the treatment of TNBC are outlined here, offering new hope for more effective and personalized therapies. Combination therapies that may improve treatment effectiveness and eventually overcome resistance are discussed. The study also outlines the challenges posed by resistance mechanisms, tumor heterogeneity, and the identification of predictive biomarkers and provides statements regarding the future direction of therapy in TNBC, with a focus on personalized medicine.

Key words: Triple-negative breast cancer, Immune checkpoint inhibitors, PARP inhibitors, PI3K/AKT/mTOR pathway, Androgen receptor inhibitors