De-escalating axillary surgery in early-stage breast cancer.

The role of axillary surgery has evolved over the last three decades from routine axillary lymph node dissection (ALND) to sentinel lymph node biopsy to omission of axillary surgery altogether in select patients. This evolution has been achieved through the design and conduct of multiple clinical trials demonstrating that ALND does not impact survival and is not necessary for local control in patients with early-stage breast cancer and limited nodal involvement. Importantly, this practice-changing shift mirrored the trend towards earlier stage at diagnosis and the recognition of the interplay between local and systemic therapies in maintaining local control. There are numerous clinical scenarios today in which axillary staging can be safely avoided, including (1) DCIS treated with lumpectomy, (2) at the time of contralateral prophylactic mastectomy, and (3) in elderly patients with early-stage, HR+/HER2-clinically node-negative (cN0) disease. Ongoing clinical trials seek to expand the cohorts in which surgical nodal staging can be omitted. These populations include a broader range of early-stage, cN0 patients undergoing upfront surgery, as seen in the SOUND, INSEMA, BOOG 2013-08, SOAPET and NAUTILUS trials. Omission of axillary surgery in cN0 patients with HER2+ or triple-negative disease treated with neoadjuvant chemotherapy is also being tested in the ASICS and EUBREAST-01 trials. Continued advances in imaging and the growing role of genomic assays in selecting patients for systemic therapy are likely to further minimize the need for axillary surgery; thereby further reducing the morbidity of local therapy for women with breast cancer.