Cases of colorectal cancer in people under 50 are increasing in many countries, alarming health experts. A recent international study found rising incidence in 27 of 50 countries through 2017, while researchers point to lifestyle factors, obesity and inherited genetic risks, and highlight new non‑invasive tests that could help close screening gaps.
Colorectal cancer, long viewed as a disease that mainly affects older adults, is increasingly being diagnosed in younger people, prompting concern among clinicians and researchers. Public attention grew after the 2020 death of actor Chadwick Boseman at age 43 from colon cancer, which highlighted that people under 50 can also be at risk.
A large international study led by American Cancer Society researchers and published in The Lancet Oncology analyzed population-based cancer registry data from 50 countries and territories and found that early‑onset colorectal cancer incidence is rising for adults aged 25 to 49 in 27 of them. The analysis, which used data through about 2017, reported the highest incidence rates for early‑onset disease in Australia, Puerto Rico, New Zealand, the United States and South Korea, with the lowest in Uganda and India.
According to that study and related expert commentary, the highest overall incidence remains in North America, Europe and Oceania, but increases are occurring across a range of regions, including parts of Eastern Europe, South‑Central and Southeastern Asia, and South America. Researchers say the global pattern likely reflects broad changes in daily life, including diets high in ultra‑processed foods, red and processed meats and sugary drinks, as well as reduced physical activity and other environmental and lifestyle factors. Obesity, which is linked to chronic inflammation and metabolic changes, is considered a key modifiable risk factor.
Scientists also stress that inherited risk plays an important role for a subset of younger patients. Hereditary syndromes such as Lynch syndrome and familial adenomatous polyposis, which involve pathogenic variants in tumor‑suppressor or DNA‑repair genes, substantially increase lifetime colorectal cancer risk and can lead to cancers at younger ages. Symptoms such as persistent changes in bowel habits, blood in the stool, unexplained weight loss and abdominal pain may be overlooked or attributed to benign conditions in younger adults, contributing to delays in diagnosis.
"Identifying a hereditary mutation allows us to implement lifelong clinical monitoring and early intervention, which can markedly improve outcomes," said Dr. Alexei Tsukanov, head of the Laboratory of Genetics at the National Medical Research Center for Radiology in Russia, in comments provided by BGI Genomics.
Non‑invasive stool‑based tests are emerging as potential tools for earlier detection, particularly where colonoscopy uptake is low. One example highlighted by BGI Genomics is its COLOTECT® Stool DNA Methylation Test, which analyzes methylation markers such as SDC2, ADHFE1 and PPP2R5C in stool DNA to help identify colorectal cancer‑related changes at an earlier stage.
Screening access and participation vary widely around the world. In parts of Eastern Europe and Central Asia, organized colorectal cancer screening remains uneven. According to information summarized by BGI Genomics, countries including Kazakhstan, Lithuania, Latvia and Georgia have established national screening programs, while others rely primarily on opportunistic testing, meaning many cancers are still detected at later stages.
Education is seen as critical to improving early detection. "To improve early detection, we must educate both healthcare providers and the public about the importance of screening," said Jemma Arakelyan, an advisor at the Immune Oncology Research Institute and CEO of The Institute of Cancer and Crisis in Armenia, in the same report.
Experts say that reversing the rise in early‑onset colorectal cancer will require a combination of strategies: promoting healthier diets and physical activity, expanding access to evidence‑based screening and genetic counseling, and improving awareness of symptoms in both patients and clinicians.
