04/12/2025
This AIRC lecture is part of a series of lectures complying with AIRC's commitment “finding the cure of cancer through research”.
The lecture “Immune effects of ionizing radiation” will be given by Dr. Silvia C. Formenti Professor of Radiation Oncology and Medicine, Meyer Cancer Center, Weill Cornell Medicine on December 4 at 5.00 pm Italian time.
Lecture abstract:
Focal radiation therapy elicits inflammatory and immune responses that contribute to cancer immunosurveillance, but may also have unwanted systemic effects. The focal application of ionizing radiation to cancer, which is the basis for the field of radiation oncology, has evolved to define and exploit the therapeutic window between radiation cytocidal effects in tumors versus those in normal tissue. The standardization of specific dose-fractionation regimens reflects the results of decades of empirical experience to find the best balance between local control of the irradiated cancer and the mitigation of risk for acute and late sequelae in the exposed normal tissues. More than a century of research in radiation biology has elucidated how radiation damage recruits a classical inflammation response, activates pathways to repair tissues through scavenging of cellular debris and canonical wound repair mechanisms that aim at recovering tissue integrity. Through tissue damage and inflammation it also recruits a strong tolerance response. Intrinsic to these process is a robust dampening of immunogenic signals, to prevent triggering of auto-immune rejections of inflamed tissues.
At the same time, cancer radiotherapy has pro-immunogenic effects, that recruit both the innate arm of the immune system (acute induction of IFN pathways) and the adaptive arm, through transcription/translation of radiation-induced epitopes and their enhanced cross presentation. Strategies to uncouple these opposite effects are the focus of research efforts in multiple radiation biology laboratories and in the clinic, worldwide.
For instance, clinical evidence has demonstrated a new role for focal radiotherapy, to partnering and synergize with immune checkpoint blockade (ICB). Both preclinically and in the clinical setting the optimal integration of radiotherapy with the available immune modifiers might require changes in standard radiation oncology practices. Variables like the type of treatment fields, the inclusion of draining nodal stations, the mitigation of exposure of circulating immune cells, the type of dose-fractionation and the timing of radiotherapy during ICB all can affect the success of immune-radiotherapy combinations. To this end interference with the immunosuppressive effects of radiotherapy, like inhibition of adenosine-associated pathways, is emerging as a promising approach.
All lectures will be through remote participation and conducted virtually using the platform AIRC Science Seminars.
To attend the lectures, please sign up at https://scienceseminars.airc.it/it/login.html
The calendar of next lectures is available at https://scienceseminars.airc.it/it/next-events.html