Colorectal cancer in under-50s is increasing at a concerning rate across several countries, according to recent medical research, yet specialists say the exact cause remains unclear.
The issue has drawn renewed attention following the death of US actor James Van Der Beek at age 48 after a battle with colorectal cancer. Actor Chadwick Boseman also died from the same disease in 2020 at 43.
Health experts stress that while the trend is worrying, most cases of colorectal cancer still occur in older adults. However, the steady rise among younger people has prompted changes in screening guidelines and intensified research into possible causes.
What Do the Latest Figures Show About Colorectal Cancer in Under-50s?
Research published in the Journal of the American Medical Association indicates that colorectal cancer is now the leading cause of cancer-related death among people under 50 in the United States.
According to Professor Helen Coleman, a cancer epidemiologist at Queen’s University Belfast, diagnoses in people under 50 have risen by roughly one third since the 1990s. However, she emphasized that the increase began from a relatively low base.
Only about six percent of all colorectal cancer cases are diagnosed in people under 50, based on research conducted in Northern Ireland. In contrast, rates among older adults have stabilized or declined in some regions due to improved screening programs.
A separate report by the American Cancer Society found that colorectal cancer diagnoses among people younger than 55 nearly doubled as a share of total cases, rising from 11 percent in 1995 to 20 percent in 2019. The proportion of advanced-stage diagnoses also increased during that period.
Experts note that although the absolute numbers remain lower than in older populations, the consistent upward trend is medically significant.
What Could Be Driving Early-Onset Colorectal Cancer?
Lifestyle Factors Under Review
Colorectal cancer has long been associated with several known risk factors, including:
Excess body weight
Diets high in processed meats
Low physical activity
Smoking and alcohol consumption
Diabetes and metabolic disorders
Doctors from institutions such as Memorial Sloan Kettering Cancer Center and Johns Hopkins Medicine have told AFP that these factors may contribute to the rise. However, specialists caution that lifestyle factors alone do not fully explain the rapid increase seen over a relatively short period.
Professor Coleman said the magnitude of change suggests that additional environmental or biological factors may be involved.
The Role of the Gut Microbiome
Researchers are increasingly examining the gut microbiome, the ecosystem of microorganisms living in the digestive tract.
A study published in the journal Nature identified DNA mutations linked to a toxin called colibactin, produced by certain strains of E. coli bacteria. These mutations were found more frequently in younger colorectal cancer patients compared to older ones.
However, scientists stress that further research is required. It remains unclear whether younger individuals are more exposed to such toxins or whether other environmental triggers are involved.
Some studies have also explored a possible link between repeated antibiotic use and early-onset colorectal cancer, though no definitive conclusion has been reached.
Jenny Seligmann, a colorectal cancer researcher at the University of Leeds, said that the diversity of cancer subtypes observed in younger patients suggests there is unlikely to be a single cause.
Symptoms and Screening Guidelines
Key Warning Signs
Medical specialists advise individuals to consult a doctor if they experience:
Blood in the stool or rectal bleeding
Persistent diarrhea or constipation
Unexplained weight loss
Ongoing abdominal pain
Iron-deficiency anemia
A sensation of incomplete bowel emptying
Doctors note that while many of these symptoms can have non-cancerous causes, persistent or unusual changes should not be ignored.
When Should Screening Begin?
In response to rising cases, the United States lowered the recommended starting age for routine colorectal cancer screening from 50 to 45 in 2021. The change followed data showing increased diagnoses among people in their late 40s and early 50s.
In the United Kingdom and France, national screening programs generally begin at age 50.
Screening methods include:
Colonoscopy, which allows detection and removal of pre-cancerous polyps.
Stool-based tests conducted annually or every few years depending on type.
CT colonography, sometimes referred to as virtual colonoscopy.
According to the US Centers for Disease Control and Prevention, early detection significantly improves outcomes. Localized colorectal cancer that has not spread can have very high cure rates, while advanced-stage disease is more difficult to treat.
Doctors emphasize that individuals with a family history of colorectal cancer or inflammatory bowel disease may require earlier screening.
Conclusion:
While colorectal cancer in under-50s remains less common than in older adults, the steady rise over the past three decades has prompted global medical concern. Researchers continue to investigate environmental, microbial, and lifestyle factors, but no single explanation has yet been confirmed.
Health authorities underline the importance of awareness, timely medical consultation, and adherence to screening guidelines to improve early detection and outcomes.
