Triple negative breast cancer: a brief review of its characteristics and treatment options.

Triple negative breast cancer (TNBC), an aggressive variant of breast cancer, is characterized by lack of expression of the estrogen (ER) and progesterone receptors (PRs) and the human epidermal growth factor receptor (HER-2) that are commonly observed in other breast cancer subtypes. The TNBC subtype primarily occurs in younger women of African American or Hispanic descent and tumors tend to be high grade and initially responsive to chemotherapy. However, TNBC is characteristically aggressive with high recurrence, metastatic, and mortality rates. Treatment options are limited since the hormonal receptor and HER-2 antagonists typically used for other breast cancers are ineffective. As such, the mainstay of treatment of TNBC is traditional systemic cytotoxic chemotherapy. Potential future therapies for TNBC include targeted molecular strategies including poly (adenosine diphosphate ribose) polymerase (PARP) and epidermal growth factor receptor (EGFR) inhibitors and antiangiogenic agents. Further research aimed at identifying unique genetic characteristics of TNBC may allow development of other targeted molecular chemotherapy treatment options.