Regional Nodal Management After Preoperative Systemic Therapy.

While historically reserved for patients with locally advanced breast cancer, the indications for preoperative systemic therapy have expanded in parallel with our increased understanding of breast cancer biology. Patient selection for preoperative chemotherapy is now primarily driven by breast cancer subtype and the incorporation of targeted therapies in HER2+ disease as well as immunotherapy in triple negative breast cancer have resulted in increasing response rates and more tailored treatment approaches. Potential benefits with respect to local therapy, now include both tumor downstaging to facilitate breast conservation as well as de-escalation of both axillary surgery and/or nodal radiation for patients who experience a pathologic complete response. Implementing these strategies requires a multidisciplinary approach and best practices for managing the breast and axilla after preoperative chemotherapy continue to evolve. Here we review the current landscape and future directions for local therapy considerations after preoperative chemotherapy.