Triple-negative breast cancer: current state of the art.

Aims And Background: Triple-negative breast cancer, defined by a lack of expression of estrogen, progesterone and HER-2 receptors, accounts for 15% of all types of breast cancer. The subtype mainly includes a molecularly distinct subgroup, the basal-like subtype (accounting for 75% of all cases). We attempt to define triple-negative breast cancer and compare it with basal-like disease, review the molecular, pathologic and clinical features of triple-negative disease, provide an overview of a retrospective subset analysis of clinical trials, and outline ongoing therapeutic trials and possible paths for future research.