Management of the Axilla after Neoadjuvant Systemic Therapy.

OPINION STATEMENT: As the use of neoadjuvant systemic therapy (NAST) increases, the optimal management of the axilla has become increasingly complex. Consensus among professional organizations is that those patients with clinically negative axillary nodes who are being considered for NAST should undergo a sentinel lymph node (SLN) biopsy following NAST. If a positive SLN is subsequently identified, an axillary lymph node dissection (ALND) is the current standard of care. For patients with clinically node-positive disease, SLN biopsy is a reasonable option for those with a good response to NAST. Patients should undergo SLN mapping with a dual dye technique. Additionally, at least 2 lymph nodes should be removed, including the previously biopsied and marked lymph node with cancer. In this setting, the identification and false negative rates are acceptable. Patients found to have a negative SLN at this time may be spared the morbidity associated with ALND. Patients found to have persistently positive lymph nodes following NAST, either clinically or pathologically, should undergo a complete ALND.