Radiation therapy and immunotherapy in breast cancer treatment: preliminary data and perspectives

Introduction: The discovery of the major role of the immune system in the tumor process has led to the development of therapeutic strategies with immunotherapy. The potential systemic role of radiotherapy, (RT) used for a long time for its local action, based on its impact on immunity, is now better understood. The combination of immunotherapy and radiation therapy is currently a field of sustained research programs and has shown successful results, in non-small cell lung cancer, for example. Breast cancer (BC) was wrongly considered poorly immunogenic and put aside during accelerating progress in this new area of treatment.Areas covered: This review provides an overview of pre-clinical and clinical rationales to associate immunotherapy with radiation therapy in the management of breast cancer.Expert opinion: Immunotherapy has been used only recently in breast cancer, but clinical trials have yet to determine the place of this treatment. RT may be useful to enhance the response of breast tumors to immunotherapy. This new approach in breast cancer management is currently based on limited data but should be further investigated, especially in triple-negative breast cancer and in the neoadjuvant setting.