Colorectal cancer becomes leading cause of cancer death in under-50s

Colorectal cancer has overtaken other cancers as the leading cause of cancer death among people under 50, according to new warnings from the American College of Surgeons. Diagnoses in younger demographics have climbed steadily, offering a stark signal for public health systems tracking shifting longevity trends.

Three decades ago, roughly 11% of colorectal cancer cases occurred in people younger than 54. That figure has now reached 20%, or one in five cases. While this data originates in the United States, European health authorities monitor these shifts closely. Rising chronic illness in working-age populations directly impacts labour productivity and strains public healthcare budgets.

A major driver of poor outcomes is delayed diagnosis. "A lot of times when younger patients seek care for bowel symptoms, those symptoms are too often attributed to hemorrhoids or constipation and treated conservatively," said Marylise Boutros, a colorectal surgeon at the Cleveland Clinic Florida and a member of the ACS Patient Education Committee.

To combat this diagnostic lag, the ACS has introduced a free public checklist designed for patients to use before primary care appointments. The tool aims to keep consultations focused and ensure subtle symptoms are not dismissed by physicians accustomed to viewing colorectal cancer as an older person's disease.

The checklist highlights specific red flags that demand medical evaluation. These include persistent changes in bowel habits, such as diarrhea or narrow stools, as well as unexplained weight loss and fatigue. "In younger patients, these symptoms can sometimes be due to noncancerous conditions," said Paula Denoya, a colorectal surgeon at Stony Brook University Hospital. "However, any bowel change that is new or different for you deserves medical attention."

Rectal bleeding is the most critical warning sign. Research presented at the ACS Clinical Congress 2025 found that in symptomatic patients under 50, recurring rectal bleeding increased the odds of a colorectal cancer diagnosis by 8.5 times. "Any amount of recurring blood should be evaluated, and colonoscopy may be indicated," said James T. McCormick, a professor of surgery at Drexel College of Medicine.

Routine screening for average-risk adults generally begins at age 45, though those with a family history start sooner. "Colorectal cancer is highly treatable when found early," Dr. Boutros said. For economies heavily invested in extending healthy working lifespans, identifying these early warning signs is a medical and financial necessity.