Utility of regional nodal irradiation in Japanese patients with breast cancer with 1-3 positive nodes after breast-conserving surgery and axillary lymph-node dissection.

Abstract

The utility of regional nodal irradiation (RNI) is being considered in cases of 1-3 axillary node metastases after breast-conserving surgery (BCS) with axillary lymph-node dissection (ALND). Therefore, we examined the necessity of RNI by examining the sites of recurrences in cases at our institution. We retrospectively analyzed 5,164 cases of primary breast cancer between January 2000 and December 2014 at the Aichi Cancer Centre, identifying local and distant recurrences in 152 patients with primary breast cancer treated with BCS and ALND and who had 1-3 positive axillary nodes. All patients received whole-breast irradiation (WBI) and adjuvant systemic therapy with either chemotherapy or anti-endocrine therapy with or without anti-human epidermal growth factor receptor 2 therapy. The present study excluded patients with ipsilateral breast tumor recurrence, contralateral breast cancer, neoadjuvant chemotherapy, T4 tumors or N2-3 nodes and distant metastasis. From the database of our institution, we identified 152 cases that met the defined criteria. The median follow-up period was 71 months (1-176). Isolated locoregional recurrences were found in three patients (2.0%) and were recurrent only in the breast. Only one patient had local lymph node recurrence with distant recurrence. The 10-year rates of isolated regional disease-free survival (DFS), DFS, and overall survival were 95.41, 89.50 and 96.75%, respectively, which was better compared with previous studies. We conclude that the addition of RNI to WBI is not necessary for Japanese patients who have 1-3 positive axillary nodes and ALND.