“…Slimane et al [216] found lung metastasis as the first site of relapse and negative hormone receptor status risk factors for brain metastasis in breast cancer patients, although other studies included young age, tumor size, stage, tumor grade, histology, and human epidermal growth factor receptor 2 (HER2, also known as neu) [187,193,[217][218][219][220][221]. Overexpression of HER2 is repeatedly supported as a risk factor for brain metastasis in breast cancer patients [57,175,193,221,222], and the risk has increased since the development of trastuzumab (Herceptin; Genentech, San Francisco, CA), a monoclonal antibody therapy [57].…”