Understanding triple-negative breast cancer

Abstract

It is estimated that over 200,000 new cases of invasive breast cancer will be diagnosed in the United States in 2012 and approximately 40,000 women will die from their disease. Triple-negative breast cancer (TNBC), which lacks expression of the estrogen receptor (ER) and progesterone receptor (PR), and does not overexpress the human epidermal growth factor receptor-2 (HER-2) represents approximately 15 % of all breast cancers and is often associated with a more aggressive underlying biology. Patients with TNBC more often experience rapid disease progression with poorer disease-related and overall survival in the first few years after diagnosis in comparison to their hormone-receptor positive counterparts. Furthermore, this subset of breast cancers has limited therapeutic options aside from traditional cytotoxic chemotherapy agents as they do not benefit from generally well-tolerated endocrine-targeted therapies and anti-HER2 drugs. In this chapter we will review the epidemiology, risk factors, prognosis and the varied molecular and clinicopathologic features that characterize TNBC. In addition this review summarizes the available data for the use of cytotoxic chemotherapy in the treatment of TNBC and explores the ongoing development of targeted therapeutic agents for the treatment of this subgroup of breast cancers.