Background: Triple negative phenotype (TNP) breast cancers are characterised by the lack of expression of oestrogen and progesterone receptors and of human EGF receptor 2 (HER2) overexpression/amplification. This subgroup of cancers has an aggressive clinical behaviour and is associated with poorer overall survival compared with other subtypes. Given the lack of targets for current tailored therapies in TNP tumours, chemotherapy is the only systemic treatment available; however, overall outcomes remain poor. Therefore, optimal treatment regimens and targeted therapies are urgently needed.
Objective: We discuss characteristics of TNP cancers that underpin the rationale of current and novel therapeutic strategies, and an approach for finding and validating new therapeutic targets.
Results/conclusion: The results of large prospective randomised controlled trials are currently awaited. Efforts to unravel the heterogeneity and complexity of TNP cancers using the latest high-throughput molecular techniques and integrating these findings with biology-driven therapeutic strategies in clinical trials will be of paramount importance for the development of treatment approaches for this breast cancer subtype.