A Rising Threat: Early-Onset Colorectal Cancer on the Rise Worldwide

Colorectal cancer has long been considered a disease of older adults. But new research shows that younger generations are facing a very different reality.

A study published in the Journal of the National Cancer Institute examined colorectal cancer trends in Australia, Canada, England, and the United States, and the findings are striking. While incidence rates among older adults have leveled off—or even declined—in recent decades, cases in adults under 50 have been climbing steadily. In fact, people born around 1990 face five to seven times higher risk of developing colorectal cancer before age 50 than those born in 1960.

The sharpest increases were seen in the youngest age groups, especially those in their 20s and early 30s. Researchers found this pattern to be consistent with a “cohort effect,” meaning that something about more recent generations’ early-life exposures is fueling the rise. Although the exact causes remain unclear, possible contributors include childhood obesity, dietary shifts, sedentary lifestyles, antibiotic use, and changes in the gut microbiome. These factors may be acting earlier in life than previously recognized, setting the stage for disease decades later.

Equally concerning is the speed of change. Across the four countries, early-onset colorectal cancer rates have been climbing at an average of nearly 5 percent per year, with women experiencing slightly faster increases than men. At this pace, cases could double every 15 years if the trend continues.

While the absolute risk for younger adults remains lower than for older adults, the upward trajectory suggests a mounting burden as these younger cohorts age. Researchers emphasize the urgency of pinpointing causes and identifying effective prevention strategies.

This study underscores an urgent reality: cancer control efforts must adapt to a shifting landscape where prevention and early detection are not just for older adults.

Read the full article here.