The following three parameters showed significant associations with long survival in the multivariate analysis (Table 2): positive HER2 status in brain metastases (aOR 5.27, 95% CI 1.50–18.55, p = 0.010), time interval ≥ 3 years between breast cancer and brain metastases diagnosis (aOR 6.13, 95% CI 1.53–24.54, p = 0.010) and preoperative KPS ≥ 90% (aOR 4.36, 95% CI 1.12–16.92, p = 0.034). The gene discussed is ERBB2; the disease is breast cancer.