Does regional lymph node irradiation improve the outcome of N0 and pN0 breast cancer?

This study compares the outcome of 76 patients with N0 breast carcinoma, node-negative at axillary lymph node dissection (pN0) after neoadjuvant chemotherapy (NeoCT), treated with (RLNI+, 39 patients) or without (RLNI-, 37 patients) elective regional lymph node areas irradiation. For RLNI- and RLNI+ groups respectively at 10 years, survival without local-regional recurrence was 95% and 91% (p = .59), survival without distant metastasis was 97% and 78% (p = .018) and overall survival was 96% and 75% (p = .013). Clinical size < 4 cm was a strong pronostic factor.