Triple negative breast cancer: proven and promising systemic therapies

Triple-negative breast cancer (TNBC) is a heterogeneous disease. While simply defined by immunohistochemical parameters, TNBC actually encompasses a raft of tumour subtypes with variable prognoses and treatment sensitivities. Systemic treatment decisions for patients with TNBC are becoming increasingly complex. In many cases, decision-making remains hampered by the current lack of predictive and prognostic biomarkers, and as such, chemotherapy remains the mainstay of systemic treatment options. Sequential anthracycline and taxane regimens, delivered as either neoadjuvant or adjuvant therapy, are widely accepted as the 'standard of care' in early stage disease. TNBC in BRCA1 and BRCA2 mutation carriers are more likely to be sensitive to platinum-based chemotherapy and PARP inhibition. The role for these approaches is currently under investigation in large clinical trials for this population. As with certain other solid tumours, harnessing the immune system to tackle this challenging breast cancer subtype is showing some promise and the role of immunotherapy in TNBC is currently being investigated in large clinical trials. Data on safety and efficacy are eagerly awaited but will need to take into account the heterogeneous nature of this disease.