ERBB2 and breast cancer: In contrast to the findings for patients with HER2+ or TNBC, the FNRs of SLNB were > 20% in both complete and non-complete responders of HR+ HER2− breast cancer, suggesting that axillary surgery should not be guided by SLNB, regardless of the radiologic response to node-positive HR+ HER2− breast cancer after NAST.