New research finds that people who survived cancer as children or young adults show signs of faster biological aging, and that this accelerated aging ties to trouble with memory and attention. Scientists measured chemical marks on DNA to estimate biological age and compared those results with cognitive testing. The strongest link to aging came from chemotherapy, and researchers are now focused on when these changes start so they can try to intervene.
Scientists studied blood samples from about 1,400 long-term survivors treated at a major pediatric cancer center to look for signs of cellular aging. Most participants were survivors of acute lymphoblastic leukemia or Hodgkin lymphoma and had been off treatment for at least five years. The team used epigenetic clocks, which read chemical tags on DNA to estimate how old cells appear biologically.
Biological age reflects the wear and tear on cells, not how many birthdays someone has had, and it can drift away from chronological age after major medical events. Treatments that damage DNA or disrupt normal cell repair can push biological age higher than expected. That gap between biological and chronological age is what the researchers were trying to quantify.
All participants also completed neurocognitive testing that measured attention span, memory, and information processing speed. Those tests were designed to capture the kinds of thinking skills that matter for school, work, and daily life. Comparing test scores with the epigenetic clocks made a clear pattern emerge: higher biological age often went with poorer performance on memory and attention tasks.
Chemotherapy showed the biggest association with accelerated aging, consistent with the idea that powerful cancer drugs can injure healthy cells even while they attack tumors. “Chemo poisons and damages cellular function — hopefully the cancer cells more than normal cells, but there is a significant impact on normal cells as well,” said Siegel, who was not involved in the study. That cellular damage appears linked to the cognitive complaints survivors commonly report.
“It’s no surprise to find out that young people with cancer who have chemo early in life are affected in terms of long-term aging,” the study quoted a medical analyst as saying, reflecting a broader medical concern about late effects. Survivors who measured older on the epigenetic scales tended to report or show measurable declines in memory and attention. That connection echoes findings in older non-cancer groups, where similar biomarkers predict decline in aging-related cognitive domains.
“These well-established aging-related biomarkers have previously been associated with neurocognitive impairment and decline in older non-cancer populations, particularly in cognitive domains related to aging and dementia, such as memory, attention and executive function,” the study stated. That wording links the new childhood-cancer survivor data to a larger body of research on how biological aging affects the brain. It also helps explain why investigators are concerned about decades of life ahead for these survivors.
The team acknowledged several limitations in their approach, including that they could not fully account for chronic health conditions or education because those factors are themselves shaped by cancer and its treatment. The research also took measurements at a single point in time, so it cannot prove cause and effect. Still, the associations were strong enough to raise questions about timing and prevention.
“Young cancer survivors have many more decades of life to live,” lead study author AnnaLynn Williams, PhD, said in a press release. “If these accelerated aging changes are occurring early on and setting them on a different trajectory, the goal is to intervene to not only increase their lifespan, but improve their quality of life.” The paper was published in Nature Communications and points toward follow-up work that will try to pinpoint when aging shifts begin and what might blunt their impact.
