Colorectal Cancer Now Leading Cancer Killer Among Younger Adults

Colorectal cancer has become the leading cause of cancer-related deaths among Americans under age 50, according to new research published in the medical journal JAMA.

The study found that deaths from colorectal cancer among younger adults have been rising steadily since 2005, increasing about 1.1 percent each year. Researchers say the trend marks a troubling shift, as the disease has historically been more common in older adults.

Colorectal cancer, which affects the colon or rectum, was once considered a condition that primarily developed later in life. However, doctors across the United States have reported a growing number of cases among people in their 20s, 30s, and 40s.

Health experts say the reasons behind the increase are still being studied. Possible factors include diet, obesity, sedentary lifestyles, environmental exposures, and changes in the gut microbiome. Genetics may also play a role for some patients.

Symptoms of colorectal cancer can include persistent changes in bowel habits, blood in the stool, abdominal pain, unexplained weight loss, and fatigue. Because many younger adults do not expect to develop the disease, symptoms are sometimes overlooked or mistaken for less serious conditions, leading to later diagnoses.

Medical organizations have already responded to the rising trend. The American Cancer Society now recommends that average-risk adults begin colorectal cancer screening at age 45, rather than 50 as previously advised.

Doctors emphasize that early detection dramatically improves survival rates. Screening tests, such as colonoscopies or stool-based tests, can identify cancer at early stages or detect precancerous growths called polyps before they develop into cancer.

Health professionals encourage people of all ages to discuss screening with their doctors, particularly if they have a family history of colorectal cancer or experience persistent digestive symptoms.

Researchers say continued awareness and earlier screening may help reverse the rising death rate among younger adults in the years ahead.