The evolving role of trastuzumab emtansine (T-DM1) in HER2-positive breast cancer with brain metastases

Abstract Approximately 30–50% of advanced human epidermal growth factor receptor 2 (HER2) positive breast cancer patients will develop brain metastases (BMs) during the disease course. Brain metastases may become a main limitation of life expectancy and a half of them will die from brain progression. Even in patients with early HER2-positive breast cancer managed with curative therapy, the risk of brain metastases is also increased. Central nervous system (CNS) may usually present as the first site of recurrence in HER2-positive breast cancer. Local treatments including radiotherapy and surgery are essential while new chemotherapy and biological agents appear to contribute a significant role in the future treatment field of CNS metastases. This article will review recent progresses in HER2-positive breast cancer with BM, with a focus on the efficacy of the HER2 targeted agents-trastuzumab emtansine (T-DM1).