Characteristics of patients with brain metastases from human epidermal growth factor receptor 2-positive breast cancer: subanalysis of Brain Metastases in Breast Cancer Registry

•Patients with HER2-positive BMs from breast cancer have the best prognosis compared with other tumor subtypes.•Among HER2-positive patients, hormone receptor-positive patients have the longest survival.•HER2-targeted therapy is significantly associated with a better prognosis in patients with BMs.•On average, two HER2-targeted therapy lines were administered prior to the development of BMs.•New compounds are urgently needed to improve the outcome of this subgroup of patients.