ERBB2 and breast cancer: Among all patients diagnosed in 2010 or later, the prevalence of lymph node metastases was 30.9% for those with ER+/HER2− breast cancer (N = 693,686), was 34.0% for those with triple-negative (ER−/PR−/HER2−) breast cancer (N = 30,185) and was 40.3% for those with HER2+ breast cancer (N = 44,897).