Triple negative breast cancer: current understanding of biology and treatment options

PURPOSE OF REVIEW: We have made remarkable advances in treatment of breast cancer with combination chemotherapies, hormonal therapies, and modern targeted therapies. Triple negative breast cancers carry a poor prognosis, however, and they are insensitive to most available hormonal or targeted therapeutic agents thus far developed. A better understanding of pathophysiology, natural history, and currently available treatment options is necessary to improve outcomes of patients with triple negative breast cancer. RECENT FINDINGS: Gene expression profiling has allowed us to classify breast cancers into five subtypes based upon distinctive gene expression signatures. This subtyping is prognostic, and the recent literatures suggest that these 'molecular portraits' may be used to predict treatment outcomes in the future. SUMMARY: As we prepare for an era of targeted and individualized medicine, limited understanding of triple negative breast cancer biology presents a challenge in developing novel therapies. Identification of more molecular predictive signatures and their prospective validation will enable us to characterize triple negative breast cancers better and design optimal treatment modalities.