“Targeting” Triple-Negative Breast Cancer: The Lessons Learned From BRCA1-Associated Breast Cancers

Breast cancer has long been recognized as a heterogeneous entity, with distinct subsets characterized by differences in tumor biology and response to therapy. With the advent of molecular profiling, we have gained a further appreciation of the heterogeneity of this complex disease. While the last decade has seen advances in the treatment of hormone receptor (HR) and human epidermal growth factor receptor 2/erb-B2 (HER2)-positive breast cancers, outcomes for women with estrogen receptor (ER)-, progesterone receptor (PR)-, and HER2-negative-or “triple-negative”-breast cancer (TNBC) remain poor. A better understanding of the shared biology of BRCA1-associated breast cancer and sporadic TNBC holds much promise for changing the outlook for women with this aggressive disease. This review focuses on our current understanding of the clinicopathological features of TNBC, therapeutic options and ongoing research efforts.