Omission of Axillary Surgery for Low-Risk Breast Cancer.

Landmark trials have demonstrated that residual microscopic disease in the undissected axilla does not translate to a higher risk of nodal recurrence, which laid the groundwork for trials examining the omission of axillary surgery. The SOUND and INSEMA randomized trials demonstrated no difference in disease-free survival in patients with small, cN0 breast cancer treated with or without sentinel lymph node biopsy (SLNB). Postmenopausal patients with luminal breast cancer undergoing lumpectomy with a normal preoperative axillary ultrasound are ideally suited for omission of SLNB, as systemic therapy decisions are increasingly based on genomic assays rather than pathologic nodal status.