New targets for triple-negative breast cancer.

Triple-negative breast cancer (TNBC) lacks the three most commonly targeted receptors in human breast cancer--the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)/neu--and it is associated with an aggressive natural history. More recently, TNBC has been further dissected into smaller, distinct subsets with unique molecular alterations and response to therapy. Large-scale genomic projects have yielded new knowledge about the molecular characteristics of TNBC, including similarities with high-grade serous ovarian cancers, suggesting a possible coordinated treatment algorithm for these malignancies. Moreover, translation of preclinical findings has led to clinical trials testing a plethora of targets and pathways in TNBC, which will be reviewed here; these include epidermal growth factor receptor (EGFR), angiogenesis, DNA repair capacity, epigenetic regulation, androgen receptor (AR) and folate receptor (FR) signaling, cell-cycle control, and cell survival. Given the complexity of TNBC biology and the lack of "traditional" therapeutic targets, the advancement of care for women with TNBC will require a true partnership between clinicians, translational investigators, and basic scientists.