The risk of developing any type of cancer increases with age, with more than 1 in 100 people over 60 diagnosed with the disease, according to the National Institutes of Health.
However, in recent years, there has been a concerning rise in gastrointestinal (GI) cancers — which affect the digestive system — among individuals under 50. The exact cause of this trend remains unclear.
A recent analysis of multiple studies found that early-onset colorectal cancer cases in the US rose by 14.8% between 2010 and 2019, with similar trends being observed globally.
Published in The British Journal of Surgery, the comprehensive review suggests that environmental influences, diet, and lifestyle may be contributing to this increase, though no specific cause has been confirmed.
Dr Anton Bilchik, a surgical oncologist and Director of the Gastrointestinal and Hepatobiliary Programme at Providence Saint John’s Cancer Institute in Santa Monica, CA — who was not involved in the study — proposed several possible explanations for the rise in GI cancers among younger adults.
“While the increase in obesity is associated with a major increase in early-onset colorectal cancer, the majority of patients are not obese, do not have a family history or any other obvious risk factors,” Bilchik told Medical News Today.
Researchers have highlighted that the sharpest rise in early-onset cancers has been seen in colon and rectal cancers. Individuals born in 1990 are more than twice as likely to develop colon cancer and over four times as likely to be diagnosed with rectal cancer compared to those born in 1950.
The increase in colorectal cancer rates is being observed globally. One study spanning 20 European countries found that between 2004 and 2016, cases rose by nearly 8% among people aged 20–29, close to 5% in those aged 30–39, and 1.6% in the 40–49 age group.
Even more alarming are statistics from the CDC’s Wonder database in the US, which reported a 333% surge in colorectal cancer cases among 15–19-year-olds and a 185% increase in those aged 20–24.
