Cancer is rising among younger generations worldwide, and scientists are uncovering clues as to why.
A new study from Washington University School of Medicine in St. Louis, drawing on tens of thousands of participants in the UK and the US, suggests that the risk of developing cancer isn't just a matter of birthdays; it's about how fast bodies age biologically.
An analysis of 154,000 records in the UK Biobank suggests younger people are aging biologically faster than older people. This systematic aging, the relative cellular and molecular age of our bodies, has also been rising across generations since birth cohorts. Crucially, this accelerated aging was associated with early‑onset cancers, particularly lung, digestive and uterine cancers, independent of their genetic predisposition.
The larger the gap between a person's biological and chronological ages, the higher the cancer risk. They also discovered that faster aging in specific organs raises risks for certain cancers: an immune system that ages too quickly was linked to early-onset lung cancer, while fat tissue aging faster than expected was tied to early-onset colorectal cancer.
To measure biological aging, the researchers studied it at two levels: the whole body and individual organs. The first, known as systemic aging, shows how fast the body overall is aging compared to chronological age. To estimate this, they used established tools such as PhenoAge, which relies on nine blood chemistry markers, including albumin (produced by the liver) and creatinine (filtered by the kidneys).
Using the Klemera–Doubal Method, the team estimated age differences from physiological data and a metabolomic age score, which reflects how a person's metabolism compares with expected norms.
The researchers used blood proteomic data to estimate how quickly different organs were aging, based on protein levels associated with each organ system. They calculated the average biological age gap for each birth cohort and used standard deviation to show how much each group differed from the overall average.
It was found that younger generations are aging biologically faster, and this accelerated aging is linked to higher cancer risk. In the UK, people born between 1965 and 1974 had bodies that were about 23% "older" than those born in the early 1950s, even at the same chronological age.
Data from the US indicate that people born in the 1990s are approximately 92% older biologically than those born in the late 1960s. This faster aging was linked to a greater risk of early-onset cancers, especially lung, gastrointestinal, and uterine cancers, suggesting that certain organs may be more vulnerable to premature aging.
Accelerated biological aging, independent of genetics, is associated with a 15% increased early-onset solid cancer risk (odds ratio 1.15). Notably, early-onset lung cancer is associated with premature immune aging (hazard ratio 1.89) and accelerated fat tissue aging for early-onset colorectal cancers (HR = 1.60).
A molecular epidemiologist, Yin Cao, states, "If we can identify younger people with the highest cancer risk when they are still healthy, we can focus on prevention and early-detection strategies for the individuals who will benefit most from early interventions."
Factors like lifestyle, environment, and metabolic stress may accelerate aging long before traditional risks such as family history or chronological age take effect. The increasing frequency of early-onset cancers worldwide calls for the identification of generational drivers like diet, pollution, and inactivity that move biological clocks forward and thereby drive young people to cancer.
Cancer risk is no longer just about how many birthdays you've had. Collectively, by tracking systemic and organ-specific aging, the goal is to develop targeted prevention strategies that slow biological wear and tear and diminish cancer risk in future generations.
This research was published in Nature Medicine.
Source: WashU Medicine
Fact-checked by Mike McRae
