ERBB2 and breast cancer: The following factors were significantly associated with a longer survival: stereotactic therapy of BM (HR 0.49 95 %CI 0.3–0.79, P = 0.004) and whole brain irradiation (WBRT) (HR: 0.58, 95 %CI: 0.42–0.80, P = 0.001) vs. no radiotherapy of the CNS metastases, endocrine therapy in patients with a HR + BC (HR: 0.31, 95 %CI: 0.21–0.45, P < 0.001) as well as HER2-targeted therapy for patients with a HER2+ BC (HR 0.41, 95 %CI: 0.25–0.68, P < 0.001, Table 4).