"With improved systemic control and prolonged survival, the incidence of brain metastases has increased, and CNS disease, often in the setting of well-controlled extracranial disease, is proving to be an increasingly important and clinically challenging cause of morbidity and mortality in patients"
"finding new treatments that target BM has not been prioritized, and nearly all clinical trials have excluded these patients. However, as patients live longer due to advances in human epidermal growth factor receptor-2 (HER2)-targeted and systemic therapy, it appears that the incidence of BM is increasing"
"Because trastuzumab does not cross the blood–brain barrier (BBB), the CNS serves as a sanctuary for metastatic disease in the setting of sustained extracranial control and improved survival."
"treatments for HER2-positive BM are a growing unmet clinical need deserving of dedicated clinical trials evaluating novel therapeutics and strategies"
"observational data suggest that HER2-positive cells may exhibit tissue tropism that cannot be explained by circulatory patterns"
"In trastuzumab-treated patients, median survival from diagnosis of CNS metastases has varied across studies, ranging from 12 to 25 months"
"Historically, BM trials have included patients with various solid tumors. There are few trials testing novel therapies specifically in breast cancer BM, and even fewer solely in patients with HER2-positive disease "
Emerging treatment options for the management of brain metastases in patients with HER2-positive metastatic breast cancer
http://www.ncbi.nlm.nih.gov/pmc/arti...960/#Abs1title