While the risk of developing any type of cancer generally increases with age, with more than 1 in 100 people over 60 diagnosed, there’s a troubling new trend: a significant rise in gastrointestinal (GI) cancers—which affect the digestive system—among individuals under the age of 50. The precise reasons behind this alarming shift remain unclear.
A recent extensive analysis, encompassing multiple studies, revealed that early-onset colorectal cancer cases in the US surged by 14.8% between 2010 and 2019, a trend mirrored globally. The comprehensive review, published in The British Journal of Surgery, suggests that environmental influences, diet, and lifestyle factors may be contributing to this increase, although no definitive cause has yet been identified.
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 aforementioned study—offered several potential explanations for this 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 specifically highlighted that the sharpest increases in early-onset cancers have been observed in colon and rectal cancers. Individuals born in 1990 are now more than twice as likely to develop colon cancer and over four times as likely to be diagnosed with rectal cancer when compared to those born in 1950.
This upward trend in colorectal cancer rates is a global phenomenon. 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 concerning are statistics from the CDC’s Wonder database in the US, which reported a staggering 333% surge in colorectal cancer cases among 15–19-year-olds and a 185% increase in those aged 20–24.
