Colorectal cancer was once considered a disease of older adults, but that perception is changing quickly. According to a recent report discussed by Healthline, colorectal cancer is now the leading cause of cancer-related death among Americans under age 50, even as deaths from many other cancers have declined. 

Researchers say the trend is concerning because 3 out of 4 younger patients are diagnosed when the disease is already advanced, which significantly reduces survival rates. The reasons for this rise are still being investigated, but scientists believe several factors may be contributing, including lifestyle changes over the past few decades. Diets higher in processed foods and red meat and lower in fiber may increase risk, while sedentary lifestyles and rising obesity rates are also associated with colorectal cancer. 

Metabolic conditions such as diabetes and chronic inflammation linked to excess body fat may also influence cancer development. Researchers note that colon cancer in younger adults is often “sporadic,” meaning it occurs without inherited genetic mutations, suggesting environmental or lifestyle factors may be involved. Another challenge is that symptoms are sometimes dismissed in younger patients. According to experts cited by Healthline, warning signs such as rectal bleeding, unexplained abdominal pain, persistent diarrhea, or iron-deficiency anemia should never be ignored, regardless of age.

Because of this rising trend, national screening recommendations have changed. The American Cancer Society now recommends that most adults begin colorectal cancer screening at age 45 instead of 50, and earlier for those with higher risk or a family history. 

While researchers continue to study the causes of early-onset colorectal cancer, experts agree that awareness, healthy lifestyle habits, and timely screening remain the most effective tools for prevention and early detection.