ERBB2 and breast cancer: LC is increasingly common, comprising about 11–20% of CNS metastasis in breast cancer.13 Prospective studies have found a median overall survival of 9–30.3 weeks in patients diagnosed with meningeal metastasis.3,14 Hormonal status, HER2 amplification followed by trastuzumab treatment, and good initial performance status has been associated with a better prognosis in patients with breast cancer LC.