Cancer, radiotherapy and immune system

Novel paradigms emerge in oncology today. Systemic treatments are more effective and diversified along with an increased life expectancy in oligometastatic patients. Stereotactic radiotherapy using hypofractionation opens new perspectives for local tumour control. The area of radiobiology has expanded with integration of tumour microenvironment in which radiation-induced inflammation mediators and immune system play a major role. Immunity checkpoints inhibitors experience a major development. This rapidly evolving field seems involved in the abscopal effects, especially when radiation is combined with checkpoints inhibitors, as demonstrated in numerous preclinical studies and several clinical trials. Paradoxically, irradiation also produces immunosuppressive effects. This manuscript aims to report the dual effects of ionizing radiation on the immune system and reviews some results of the combination of radiation and immunity chekpoints inhibitors and also research perspectives.