Home Career Benefits of radiation to some but not all lymph nodes – ScienceDaily

Benefits of radiation to some but not all lymph nodes – ScienceDaily


Promising new research published by the University of Colorado Cancer Center suggests that the recurrence of some cancers can be significantly reduced by irradiating only a select set of lymph nodes near a tumor, rather than all of them.

The study was published today in Communications of nature.

“Doctors have traditionally irradiated all the lymph nodes surrounding the tumor in a process called ‘nodal elective radiation,'” said Sana Karam, MD, PhD, associate professor of radiation oncology at the University of Colorado School of Medicine and senior author of the study. “But the problem with this scorched-earth approach in the age of immunotherapy is that it also eliminates the source of immune cells that immunotherapy can work on. The lymph nodes are the center for the preparation and expansion of the main immune cells that can go and fight the cancer.’

Karam and her team learned that irradiating all the lymph nodes around a tumor significantly reduces immune memory and antigen dissemination, creating a much greater risk of cancer spreading to parts of the body far from the original tumor site. “It was an unexpected find,” Karam says.

The team preclinically tested this theory in several different head and neck tumor models, as well as breast cancer and melanoma models. The result was the same regardless of the type of cancer being treated. When the radiation killed the immune cells that could recognize what the cancer looked like, the patient’s immune system lost its ability to systemically fight the cancer.

On the other hand, the researchers found that radiation to certain lymph nodes, known as sentinel lymph nodes, was absolutely critical. Their lack of radiation resulted in a relapse nearby.

“This study confirms why elective nodal radiation has long been the clinical standard of care because it reduces regional recurrence,” said Laurel B. Darragh, first author of the paper and MD/PhD in Dr. Karam’s lab. “But it also shows that to effectively combine radiation with immunotherapy, we need to rethink our strategies and limit nodal radiation to the sentinel lymph nodes. This eliminates regional recurrences in the neck and distant spread while preserving a long-term systemic immune response. “

The findings were supported by data from a recent human clinical trial in which preoperative radiation is limited to the large tumor and sentinel lymph nodes, while avoiding other lymph nodes to maintain immune memory. The researchers found that the immune system in these patients was highly activated, which has been shown to correlate with a better prognosis.

“We hope that these data will lay the foundation for future clinical trial design, not only reducing patient side effects, but also improving long-term outcomes,” Karam said.

Story source:

Materials is provided University of Colorado Anschutz Medical Campus. Original written by Laura Kelly. Note: Content can be edited for style and length.

Source link

Previous articleJudge approves Sweet v. Cardona student debt settlement, but appeal likely
Next articleHow to buy on the secondary market