Therapeutic strategies for triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a clinically relevant term referring to breast carcinomas that do not express the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor type 2 and became operational after human epidermal growth factor receptor type 2 testing was introduced. This is a challenging disease to treat because of the absence of a specific target, but these tumors are sensitive to chemotherapy. An improved understanding of the biology of TNBC has led to evaluation of DNA-damaging chemotherapy drugs, specifically, platinum compounds, and several targeted agents, including poly(ADP-ribose) polymerase inhibitors, epidermal growth factor receptor inhibitors, angiogenesis inhibitors, microtubule inhibitors, Src inhibitors, checkpoint kinase I inhibitors, mammalian target of rapamycin inhibitors, androgen receptor blocker, tumor necrosis factor-related apoptosis-inducing ligand receptor agonists, and transforming growth factor-beta antagonists, that may lead to improved clinical outcomes. Ongoing clinical trials will further define the optimal chemotherapy regimen and most effective targeted therapeutic strategy for TNBC.