ERBB2 and breast cancer: Patients with HR-/HER2 + subtype breast cancer had an inferior survival, with a 3-year OS rate of 85.9% (95% CI 85.6–86.2%) and a 5-year OS rate of 78.8% (95% CI 78.3–79.3%), which was significantly decreased than that of patients from HR + /HER2 + subgroup with the a 3-year and 5-year OS rate of 90.5% (95% CI 90.3–90.7%) and 84.2% (95% CI 83.9–84.5%) (P < 0.0001) (Appendix Fig. 1a).