Postmastectomy radiation therapy in women with T1–T2 tumors and 1 to 3 positive lymph nodes: analysis of the breast international group 02-98 trial

In case of patients affected by breast cancer with more than 4 positive lymph nodes (LNs), postmastectomy radiation therapy (PMRT) has been widely adopted to reduce local relapse (1,2). Some controversies are still present regarding the use of PMRT for patients with 1–3 positive LNs. The updated meta-analysis of the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) published in 2014 regarding the effects of PMRT, performed additional analyses on 1.133 patients were affected by breast cancer with 1–3 positive LNs receiving axillary dissection and chemotherapy (3). The latter meta-analysis showed that the 10-year rate of locoregional failure was 21.0% and 4.3% for patients who received radiation therapy or not, respectively (P=0.001). The 10-year rate for any recurrence (locoregional or distant) was 45.5% and 33.8% without PMRT and with irradiation (P=0.001), and the respective 20-year rates of breast cancer mortality were 49.4% and 41.5% (P=0.01; relative risk, 0.78), respectively. The trials included in the EBCTCG meta-analysis were conducted in the 1970s and 1980s and chemotherapy used, was cyclophosphamide, methotrexate, and fluorouracil (CMF); or methotrexate plus fluorouracil; or single-agent cyclophosphamide or melphalan (Data Supplement Table 1) (3)