ERBB2 and breast carcinoma: ALN status varied by biological subtype with ypN+ disease being most common in HR-positive/HER2-negative (12/91, 13.2%) breast cancer followed by HR-negative/HER2-positive (2/30, 6.7%), HR-positive/HER2-positive (2/51, 3.9%), and HR-negative/HER2-negative (1/50, 2.0%) (p = 0.064).