Current approaches to the treatment of HER2‑positive breast cancer with brain metastases

The article discusses modern approaches in the treatment of HER2-positive breast cancer (BC) with brain metastases (BM).The patients are subject to multidisciplinary, comprehensive and biologically – oriented treatment, with the involvement of a neurosurgeon and a radiation therapist to make a decision considering local treatment of BM, as well as a clinical oncologist to choose systemic drug therapy. Local treatment of HER2+ BC with BM patients includes surgical treatment and/or radiotherapy. Use of targeted anti-HER2 therapy changes “biology” of the disease from aggressive to indolent.In the prospective KAMILLA trial, clinically significant antitumor activity of trastuzumab emtansine was found for the first time both in patients with HER2+ BC with BM, who were previously treated with radiotherapy, and without radiotherapy in the anamnesis, which suggests the validity of further use of trastuzumab emtansine in this category of patients.The antitumor activity of trastuzumab emtansine in patients with HER2+ BC with BM was also confirmed in preclinical models. Despite the similar drug distribution in the tissues, trastuzumab emtansine, in contrast to trastuzumab, significantly slowed the growth of metastases, causing the induction of apoptosis in HER2+ BC models with BM in mice.