Genomic profiling in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is defined by a lack of hormone receptor expression as well as lack of overexpression/amplification of HER2/neu. Patients with TNBC show a significantly worse prognosis compared to patients with other breast cancer subtypes. TNBC, however, is a heterogeneous entity both with regard to clinical/pathological characteristics and molecular biology. This review summarizes the current data on TNBC with a particular focus on mutational and gene expression profiling and the association between TNBC and breast cancer stem cells.