New strategies in breast cancer: the significance of molecular subtypes in systemic adjuvant treatment for small T1a,bN0M0 tumors.

Awareness of breast cancer heterogeneity has strikingly increased in the past decade in parallel with the development of high-throughput molecular tests. Beyond the clear usefulness of antiestrogen treatment in luminal tumors and trastuzumab in HER2-positive tumors, breast cancer subtypes may have additional clinical and predictive roles that can be relevant to clinical practice. In this article, we discuss the significance of molecular subtypes in the systemic treatment of early-stage breast tumors smaller than 1 cm (T1a,bN0M0) and suggest new strategies for future treatment recommendations for these patients. ©2014 American Association for Cancer Research.