Axillary staging in clinically node negative (cN0) breast cancer patients with neoadjuvant systemic therapy (NST; i.e. chemo- and immunotherapy), is preferably performed with sentinel lymph node biopsy (SLNB) after NST. The probability of a tumor-positive SLNB post-NST is low. cN0 patients with Human Epidermal growth factor Receptor 2- positive (HER2+) or triple negative (TN) breast cancer who achieve radiologic complete response (rCR) of the breast on MRI, have the lowest probability of a tumor-positive SLNB post-NST (\<3%). Omitting removal of axillary lymph nodes in clinically node negative patients does not increase the rate of distant metastases nor breast cancer mortality. Performing SLNB can cause short- and long-term morbidity, reducing quality of life. The additional value of performing SLNB in patients with a very low risk of tumor-positive axillary lymph nodes should be investigated.
