“…Guidelines of the National Comprehensive Cancer Network (NCCN) and the German Society for Radiooncology (DEGRO) recommend adjunctive RT in patients after mastectomy due to T1-2N1M0 breast cancer (Sautter-Bihl et al, 2008;National Comprehensive Cancer Network (NCCN), 2011). However, other studies, including the St. Gallen International Breast Cancer Conference, New Zealand Guidelines Group (NZGG), Chinese Anti-Cancer Association, and the European Society for Medical Oncology (ESMO), recommend adjunctive RT for patients with 1 to 3 positive ALN plus the presence of other risk factors, such as young age, negative estrogen receptor (ER) status, dissection of a small number of ALN, positive nodal ratio, lymphovascular invasion (LVI), extracapsular extension, and high nuclear grade (New Zealand Guidelines Group (NZGG), 2009;Aebi et al, 2011;Goldhirsch et al, 2011; Professional Committee of Breast Cancer of Chinese Anti-Cancer Association, 2011; Huang et al, 2012;Kong and Hong, 2013).…”