Based on treatment combinations, receiving local and systemic treatment combined for both BM and BC achieved the highest OS at 19.02 (17.08–20.70), 28.94 (24.77–35.29), 19.42 (16.95–23.36), and 8.84 (7.85–9.79) for the HR( +)/HER2( − ), HR( +)/HER2( +), HR( − )/HER2( +), and HR( − )/HER2( − ) subgroups, respectively (log rank test, p < 0.0001). This evidence concerns the gene ERBB2 and breast cancer.