In the multivariate analysis, the following factors were significantly associated with a higher risk of death: age ( ≥ 60 vs. <60 years, HR: 1.65, 95 %CI: 1.25–2.18, P < 0.001), worse performance status at diagnosis of CNS metastases (ECOG 2–4 vs. 0–1 HR: 2.15, 95 %CI: 1.63–2.82), a HR+/HER2-or triple-negative tumor biology vs. triple-positive (HR: 1.54 95CI%: 1.07–2.23, P = 0.02 and HR: 1.87, 95 %CI: 1.25–2.81, P = 0.003, respectively) as well as a higher number of BM (2–3 vs. 1, HR: 1.49, 95 %CI: 1.05–2.11, P = 0.03). The gene discussed is ERBB2; the disease is neoplasm.