[Philadelphia, PA] – Cancer risk increases with age and is often more aggressive and difficult to treat in older adults. However, fewer than 10% of mouse studies use aged animals , with most relying on mice roughly equivalent to humans in their early 20s . This discrepancy is one potential reason so many cancer drugs that show promise in preclinical models go on to fail in human trials.
New research from Fox Chase Cancer Center , presented at the American Association for Cancer Research annual meeting, suggests melanoma behaves differently with age. The data showed cancer spread was the lowest in young mice, peaked in middle‑aged mice, and declined in very old mice.
“The vast majority of studies are done in these very young mice that have a healthy and intact immune system ,” said Mitchell Fane, PhD , a cancer biologist who specializes in aging and cancer, and lead investigator of the study. “Right now, it’s easy to personalize care for someone who’s young and fit, who’s potentially not going to experience as many toxicities; understanding how therapies affect older patients would give us more and better treatment options.”
Fane and his colleagues suggest that a key factor behind their findings involves a specific group of immune cells called gamma delta (γδ) T cells, which act like early warning guards that help prevent cancer from spreading. Young and very old mice had more of these protective immune cells, and their cancer was more likely to stay dormant or spread less. Middle‑aged mice had fewer γδ T cells, and their melanoma was far more likely to spread to organs like the lungs and liver.
The study also showed that melanoma cells themselves can actively weaken the immune system as animals age . In middle‑aged mice, melanoma released certain molecules that shut down or exhaust γδ T cells, allowing previously quiet cancer cells to “wake up” and spread aggressively.
Notably, when researchers removed γδ T cells from young and very old mice, melanoma spread increased, suggesting these immune cells normally help keep the cancer in check. By contrast, blocking immune‑suppressing signals restored immune protection and reduced cancer spread, but only in middle‑aged mice.
One reason few studies use older mice is that young mice are cheaper and faster to obtain. Mice must be bred and cared for about 18 to 24 months before they are old enough for aged‑mouse models.
Fane and his colleague Yash Chabra, PhD, both Assistant Professors in the Cancer Signaling and Microenvironment Research Program , helped establish an aged mouse facility at Fox Chase. Together they are providing researchers with access to better models for how cancer behaves in older patients .
“Now we have a facility with established aged mouse colonies, which lowers the cost and time barriers to aging research,” he said. “It allows us to tell colleagues, ‘Your model is interesting, why not test it in aged mice?’”
Better understanding the role of aging in cancer is a key step to developing better treatments for older patients. Fane’s lab is also interested in how the link between cancer risk and age is not linear.
“While risk increases steadily as people age, it abruptly decreases after ages 80-85, said Fane. “We want to explain the mechanism of why very old patients are getting less cancer, but middle-aged patients are getting more.”
Read the full study here: https://aacrjournals.org/cancerres/article/86/7_Supplement/2072/777378/Abstract-2072-Role-of-the-aging-on-the-T-cells-in
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Fox Chase Cancer Center (Fox Chase), which includes the Institute for Cancer Research and the American Oncologic Hospital and is a part of Temple Health, is one of the leading comprehensive cancer centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase was also among the first institutions to be designated a National Cancer Institute Comprehensive Cancer Center in 1974. Fox Chase is also one of just 10 members of the Alliance of Dedicated Cancer Centers. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are also routinely recognized in national rankings, and the Center’s nursing program has received the Magnet recognition for excellence six consecutive times. Today, Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research, with special programs in cancer prevention, detection, survivorship, and community outreach. It is the policy of Fox Chase Cancer Center that there shall be no exclusion from, or participation in, and no one denied the benefits of, the delivery of quality medical care on the basis of race, ethnicity, religion, sexual orientation, gender, gender identity/expression, disability, age, ancestry, color, national origin, physical ability, level of education, or source of payment. For more information, call 888-369-2427.
Cancer Research
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Abstract 2072: Role of the aging on the ᵧδ; T-cells in metastatic cutaneous melanoma progression.
17-Apr-2026