Radiation is commonly used to kill cancer cells.
But a team of researchers from Mayo Clinic, the University of Texas MD Anderson Cancer Center, and Stanford University School of Medicine are exploring a new use for this old therapy.
In pre-clinical findings, published in the journal Trends in Cancer, the scientists use ionizing radiation to stimulate non-cancerous cells in the area around the tumor.
Tumor cells have the ability to hide from the immune system. This characteristic may involve the cells in the vicinity of the tumor. The scientists wanted to see if radiation could be used to persuade those tumor-surrounding cells to stop camouflaging the tumor and perhaps even help by marking cancer cells for destruction.
The radiation modifies tissue properties in the area surrounding the tumor and promotes an immune response. This effectively unmasks the tumor, allowing immune cells to see it.
“We may be able to enhance the efficiency of immune-stimulating therapies to target resistant tumors by using radiation in this unusual context,” explains Betty Kim M.D., Ph.D., Mayo Clinic neurosurgeon and translational researcher. “Determining the precise dose, schedule and the target of radiation will be crucial for triggering the patient's immune cells to cooperate in this way. It will take time to validate the practicality of this approach.”
Multiple early phase clinical trials are underway that combine this unique use of radiation with drugs called immune checkpoint inhibitors, which can also help the immune system detect the tumor. Further research is needed to determine the clinical benefit of this new approach.
— John Jefferson, Ph.D., November 3, 2016