Nonsentinel lymph node metastases in cases of micrometastasis detected by sentinel lymph node biopsy after neoadjuvant chemotherapy.

The study identified a 24.2% possibility of additional non-SLN metastasis if micrometastases was detected in the SLN after NAC. This rate is significant, indicating that ALND cannot be omitted if low volume residual disease, such as micrometastasis, is identified in the SLN after NAC.