Influence of internal mammary node irradiation on long-term outcome and contralateral breast cancer incidence in node-negative breast cancer patients

IMN RT in node-negative tumours was associated with increase in OS and CSS in patients with inner or centrally located lesions. An increase in CBC development was also noticed in long-survivors of IMN RT patients; however, these findings have to be interpreted with caution because of the difference in follow-up between the 2 groups. Further studies are warranted to investigate the potential role of IMN irradiation in the development of CBC.