are treated with radiotherapy, the benefits can be hijacked by the
treatment's counteraction to trigger inflammation and dampen the body's
immune response, suggests a University of Rochester Medical Center study.
Published by the journal Oncotarget
, the study suggests that
radiotherapy (also known as radiation treatment) could be more
effective if it was combined with a drug that would block a specific
cell that is responsible for dulling the immune system. In mice, the
research team experimented by delivering an immunotherapy two days prior
to radiotherapy and saw significant benefits for many different types
‘Radiotherapy could be more effective if it was combined with a drug that would block a specific cell that is responsible for dulling the immune system.’
Led by Scott A. Gerber, assistant professor in the Department
of Surgery, and graduate student Kelli A. Connolly, the research fills
an important gap in knowledge. Scientists already know that radiotherapy
stimulates anti-tumor cells and helps to control cancer's growth. What
is less understood is why radiotherapy cannot cure cancer.
The answer may lie with how the immune system responds to
radiotherapy when a tumor is present. The URMC and Wilmot Cancer
Institute scientists discovered that radiation increases the circulation
of certain harmful inflammatory cells and changes the way the immune
system rallies against cancer.
In many patients, the circulating level
of these cells (called monocytes) is already high prior to cancer
treatment and sometimes indicates a poor prognosis.
Gerber believes that the abundance of these cells, which can be
measured in a simple blood test, could identify patients who might
benefit most from blocking them, allowing the immune system to fight the
disease in combination with radiotherapy. Because these inflammatory
cells express a unique protein on their surface, they are an easy target
for medications, the study said.
"Our observations of what happens during radiotherapy when cells are
recruited to the tumor site and surrounding tissue has intriguing
implications for how to improve treatment," said Gerber, who also has an
appointment in the URMC Department of Microbiology and Immunology.