For patients whose breast cancer converted from lymph node-positive to lymph node-negative disease after neoadjuvant chemotherapy, skipping adjuvant regional nodal irradiation (RNI) did not increase the risk of disease recurrence or death five years after surgery, according to results from the NRG Oncology/NSABP B-51/RTOG 1304 clinical trial presented at the San Antonio Breast Cancer Symposium, held December 5-9, 2023.