It’s well-known that a person’s immune system wears down over time, becoming less effective as folks progress through middle age and become seniors.
But that doesn’t appear to hinder the effectiveness of immunotherapy for cancer in seniors, a new study says.
Seniors with cancer respond just as well as younger patients to immune checkpoint inhibitors — drugs that take the brakes off the immune system so it can target and kill cancer cells more effectively, researchers reported April 21 in the journal Nature Communications.
“Older patients do just as well, sometimes better than younger patients with immunotherapy treatments,” said senior researcher Dr. Daniel Zabransky, an assistant professor of oncology at Johns Hopkins University School of Medicine.
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What is immunotherapy?
Immunotherapy harnesses the power of the body’s immune system to fight the disease. Unlike traditional therapies like chemotherapy and radiation, which directly target cancer cells, immunotherapy works by empowering the immune system to recognize and attack cancer cells.
“We found clues about important pathways mediating the immune system response to immunotherapies in younger versus older patients that may help us improve the next generation of therapies or allow us to use current therapies in all patients more effectively,” Zabransky added in a news release.
The immune system is a complex network of cells, tissues, and organs that defends the body against harmful invaders like bacteria and viruses. Cancer cells, however, can evade detection by the immune system through various mechanisms. Immunotherapy aims to overcome these evasive tactics and enhance the immune response against cancer.
Most new cancer diagnoses occur in people 65 and older, and overall these folks have worse cancer treatment outcomes, researchers said in background notes.
In part, this is because their aging immune systems make it harder for their bodies to fight cancer cells, researchers said.
But it’s unclear whether immunotherapy can help people overcome these effects of aging.
How does immunotherapy help cancer patients?
In clinical trials, immunotherapy is rigorously tested to determine its safety and effectiveness in treating specific types and stages of cancer.
For this study, researchers examined immune response in the blood of about 100 cancer patients treated with immune checkpoint inhibitors, of whom about half were 65 or older.
Immune checkpoint inhibitors are drugs that block “checkpoint” proteins on immune cells, which usually keep them from attacking healthy cells. By blocking these checkpoints, the immune system can unleash a stronger response against cancer cells.
Both groups benefited from immunotherapy equally, researchers found.
There were, however, important differences in their immune responses, the results show.
For example, hunter/killer T cells in seniors appeared less ready to respond to threats like cancer without a boost from an immune checkpoint inhibitor, researchers found.
These differences might make immunotherapy drugs even more beneficial for older patients, they said.
Researchers’ next plan is to look at differences in the immune cells found inside tumors, and compare them across age groups to see how they react to immunotherapy.
By understanding age-related differences, researchers might be able to hone new cancer therapies so they can be better targeted to patients based on age.
“Right now, we give immune checkpoint inhibitors to patients in the same way without major consideration about how their age may influence how the immune system may recognize cancer cells,” Zabransky said. “By better understanding age-related changes that we all experience over our lifespan, we hope to identify new strategies and personalize our therapies even further based on those important patient-level factors.”
Ongoing research is focused on identifying biomarkers that can predict which patients are most likely to benefit from immunotherapy and on developing new strategies to enhance its effectiveness.
More information
The National Cancer Institute has more on immune checkpoint inhibitors.
SOURCE: Johns Hopkins Medicine, news release, April 21, 2025
