Scientists explain the increase in the number of cancer diagnoses in young people

Cancer is increasingly being diagnosed in people under the age of 55, and one of the reasons may be accelerated biological aging of the body. Researchers have found that younger generations look biologically older than people of the same age from previous generations, and accelerated aging is associated with an increased risk of early development of certain cancers. About how biological age can be associated with oncological diseases, see the "Izvestia" article.

Why cancer can appear earlier

The risk of developing cancer generally increases with age: the longer a person lives, the more time cells have to accumulate damage that can contribute to the development of tumors. However, in recent years, scientists have been paying attention to an increase in the number of cancers in people under 55 years of age.

Researchers from Washington University School of Medicine in St. Louis have suggested that accelerated biological aging may be one explanation. Unlike chronological age, which is determined by the number of years lived, biological age shows how "old" an organism looks, taking into account the state of cells, organs, metabolism and other physiological processes.

Scientists found that people from younger generations, on average, had more pronounced signs of biological aging than representatives of previous generations at the same age. At the same time, a more significant difference between biological and chronological age was associated with an increased risk of developing cancer at a young age. The work was published in the journal Nature Medicine.

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How scientists determined biological age

For the study, the researchers analyzed data from more than 154 thousand young people from the British biobank. In addition, they studied information about more than 10,000 participants in the American All of Us program, created to form a large-scale database of medical and biological data.

The researchers assessed the aging of the body in several ways at once. One of the approaches allowed us to determine the systemic biological age, that is, the state of the body as a whole. Blood counts and other biomarkers were used for this purpose. The scientists also applied a metabolic age indicator that reflects the changes in metabolism associated with aging.

Separately, the researchers assessed the biological age of specific organs and systems. To do this, we used data on proteins in the blood associated with the work of various tissues. This approach allowed us to determine not only how quickly the body as a whole ages, but also which individual systems can age faster.

The difference between generations was noticeable in both populations studied. In the British sample, people born in 1965-1974 had systemic biological aging 23% of the standard deviation higher than participants born in 1950-1954. In the American sample, the difference was even more noticeable: people born in 1990-1999 had a 92% standard deviation higher than those born in 1965-1969.

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How aging is related to cancer

The scientists then checked whether the differences in biological age were related to cancer. It turned out that representatives of the younger generation with a pronounced acceleration of systemic aging had an 8% higher risk of early development of solid tumors.

A particularly significant association was observed for lung cancer, gastrointestinal tract diseases, and uterine cancer. When dividing the participants into three groups, depending on the degree of biological aging, the researchers found another pattern: people with the most pronounced signs of accelerated aging had a 15% higher risk of early development of solid cancer than participants with the least signs of such aging.

The relationship persisted even after taking into account the hereditary predisposition to cancer and the genetic tendency to accelerated aging. At the same time, scientists emphasize that the results show exactly the relationship between the indicators, and do not prove that accelerated biological aging directly causes cancer.

The researchers also found differences for individual body systems. A more pronounced biological aging of the immune system was associated with an increased risk of early lung cancer, and accelerated aging of adipose tissue was associated with the risk of colorectal cancer.

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Is it possible to determine the risk of cancer in advance

The authors of the study believe that estimating biological age in the future may help identify people who have a higher than average risk of early cancer development. This approach will potentially make it possible to start preventive measures and patient monitoring earlier, however, additional research is needed for the practical application of the method.

Scientists do not yet know why representatives of younger generations show signs of accelerated biological aging. Researchers are looking at the effects of the environment, lifestyle, and social factors that can leave lasting biological changes in the body.

According to scientists, no single factor explains the increase in cancer cases among young people. Previously, the team studied the possible role of obesity, metabolic disorders, alcohol consumption, lack of physical activity, nutritional quality, and other factors.

The researchers plan to continue studying how modern living conditions can affect biological aging and increase the body's susceptibility to diseases. Their long—term goal is to learn how to identify an increased risk of cancer even before the onset of the disease and select preventive measures taking into account the individual characteristics of the body.