The Mean 5-year OS was 88.8% ± 1.7% for HR+/HER2+ breast cancer in stage B and 93.1% ± 0.9% for the subtype-specific control group; for HR+/HER2− breast cancer patients in stage B, the mean 5-year OS was 82.1% ± 0.7% and 87.0% ± 0.4% for the subtype-specific control group; for HR−/HER2+ breast cancer patients in stage B, the mean 5-year OS was 79.2% ± 3.5% and 92.1% ± 1.7% for the subtype-specific control group; and for HR−/HER2− breast cancer patients in stage B, the mean 5-year OS was 54.1% ± 2.3% and 79.0% ± 1.4% for the subtype-specific control group. This evidence concerns the gene ERBB2 and breast cancer.