Molecular Pathways: PI3K Pathway Targets in Triple-Negative Breast Cancers

The triple-negative breast cancer (TNBC) subtype, defined clinically by the lack of estrogen, progesterone, and Her2 receptor expression, accounts for 10% to 15% of annual breast cancer diagnoses. Currently, limited therapeutic options have shown clinical benefit beyond cytotoxic chemotherapy. Defining this clinical cohort and identifying subtype-specific molecular targets remain critical for new therapeutic development. The current era of high-throughput molecular analysis has revealed new insights into these targets and confirmed the phosphoinositide 3-kinase (PI3K) as a key player in pathogenesis. The improved knowledge of the molecular basis of TNBC in parallel with efforts to develop new PI3K pathway–specific inhibitors may finally produce the therapeutic breakthrough that is desperately needed. Clin Cancer Res; 19(14); 3738–44. ©2013 AACR .