Cancer becomes more common with age and is often harder to treat in older adults. Yet most cancer studies in mice do not reflect that reality. Fewer than 10% of mouse experiments use aged animals, with researchers typically relying on mice that roughly correspond to humans in their early 20s.
That gap may help explain why many cancer therapies that perform well in laboratory studies ultimately fail in human clinical trials.
New findings from Fox Chase Cancer Center, presented at the American Association for Cancer Research annual meeting, suggest that melanoma does not behave the same way throughout the aging process. Researchers found that cancer spread was lowest in young mice, reached its highest level in middle aged mice, and then declined again 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."
