‘Accelerated aging’ could explain why some young adults develop early-onset bowel cancer

A person’s “biological age” – as opposed to their chronological age – could help explain why they develop colorectal cancer, one of the most common forms of cancer worldwide, according to the findings of a new study.

Known as “accelerated ageing”, the concept reflects the impact of genetics, lifestyle choices and environmental factors on a person’s health and is determined through sophisticated DNA analysis.

The link may help identify who is at risk of developing colon polyps, a precursor to bowel cancer, according to the study, which was conducted by researchers in the Miller School of Medicine’s Sylvester Comprehensive Cancer Centre at the University of Miami.

The discovery could underscore the case for earlier routine screening as a means of combating the rising incidence of early-onset bowel cancer in under-50s adults, and more extensive use of colonoscopies to detect and help prevent cancer.

“Biological age is an interesting concept, and it leads to the idea of accelerated aging, when your biological age exceeds your chronological age,” said Shria Kumar, a colorectal cancer researcher at Sylvester and the study’s senior and corresponding author.

For example, she explained, if someone is 50, but his or her biological age is 55, that’s five years of accelerated aging that might be reflected in overall body functioning.

“It sounds pretty theoretical, but actually accelerated aging has been shown to be predictive of time to death and even of multiple cancers,” Dr Kumar added, noting that this line of research adds to a growing area of study with epigenetics, which examines the mechanisms behind deteriorating cell functions.

The study’s findings were published in Cancer Prevention Research, a journal of the American Association for Cancer Research.

For their investigation, the researchers drew on the medical records of almost 150,000 people aged 37 to 54 who had undergone colonoscopies and who were participants in a large data registry called the UK Biobank.

They focused on nine blood-based markers that have been shown to correlate with biological age, calculating each participant’s biological age with the help of an algorithm. They then checked cancer registries to see how many in the group had been diagnosed with early cancers – that is, cancers appearing before the age of 50.

The researchers found that people born in 1965 or later were 17 per cent more likely to show accelerated aging than those born from between 1950 and 1954.

“We all know cancer is an aging disease,” said Yin Cao, an associate professor of surgery at the Washington University School of Medicine in St Louis and a senior author of the study.

“However, it is really coming to a younger population. So, whether we can use the well-developed concept of biological aging to apply that to the younger generation is a really untouched area.”

Colorectal cancer rates in adults under 50 have been rising in recent years with one recent study noting the high incidence among Australians, with that rate rising between 2 per cent and 4 per cent annually in the five years to 2017.

Since 2020, Australia has had a free national bowel screening program available to adults aged 50 to 74 with kits for collecting stool samples mailed out every two years. From July 2024, the eligible screening age was lowered to 45 years, although people under 50 are required to opt into the program.

The University of Miami study raises the question about the best time to start routine screening, while acknowledging that a colonoscopy, a more invasive outpatient procedure that requires sedation in a medical facility, produced the best results.

The latter can identify and remove polyps, which are soft-tissue growths that can lead to cancer.

“What’s really, I think, exciting about the opportunity in colorectal cancer is that we have a clear prevention tactic,” said Dr Kumar. “Colonoscopy is not only early detection, but also cancer prevention.”