Controversies in Radiation Therapy in the Era of Surgical Nodal De-escalation

Purpose of Review To examine the use of radiation therapy (RT) in studies on de-escalation of axillary surgery for patients with early-stage breast cancer, the incorporation of pathologic nodal data in RT de-escalation, and current data on omission of both axillary surgery and RT. Recent Findings In the wake of the SOUND and INSEMA trials, the 2025 ASCO Guidelines on sentinel lymph node biopsy in early-stage breast cancer expanded the recommended eligibility for omission of axillary surgery. However, ongoing RT omission trials such as DEBRA and SWIFT RT, which offer enrollment to very similar cohorts of patients with breast cancer, require documented pathologically negative nodes. Despite a paucity of randomized controlled data on de-escalation of both axillary surgery and RT, CALGB 9343 and more recent retrospective studies have demonstrated few oncologic events in such patients who have omission of both axillary surgery and RT. Summary The extent of axillary staging has been shown not to impact oncologic outcomes, yet pathologic nodal staging data is required in protocols for studies evaluating the de-escalation of RT. Modern data on omitting both axillary surgery and RT in women with low-risk breast cancers are limited to small, retrospective studies. However, the similarities between cohorts enrolled in single-modality omission studies suggest opportunities for further study identifying low-risk patients who may benefit from the omission of both therapies.