Management of the Axilla in Breast Cancer

During the majority of the last century, management of the axilla in patients with breast cancer consisted of an axillary lymph node dissection (ALND) in most patients for the purpose of staging and locoregional control. Several landmark clinical trials in the past 30 years have challenged this dogma. Surgical staging of the axilla with sentinel lymph node (SLN) surgery, which is a less morbid procedure, has been shown to be equally effective in clinically node-negative patients, with ALND reserved for patients with positive nodes. More recent evidence from the ACOSOG Z0011 trial showed that omitting an ALND in patients with low-volume nodal disease is safe in patients receiving whole-breast radiation. This and other trials have contributed to the complexity and controversy in axillary management. As the use of more effective systemic and targeted local therapy has become available, the trend has shifted toward less aggressive surgery in the axilla. Patient selection in the modern era is paramount. Contemporary trials are directed toward optimizing the management of node-positive patients who have excellent response to neoadjuvant chemotherapy. Future trials may show that axillary staging in clinically node-negative patients may not even be necessary.