Rising Early-Onset Colorectal Cancer Prompts Review of Screening Guidelines

Recent research shows a steady increase in colorectal cancer diagnoses among adults under 50. In the United States, the U.S. Preventive Services Task Force has lowered the recommended screening start age to 45, and health experts stress earlier testing for those with family history.

A Swiss nationwide study of 96,410 cases between 1980 and 2021 found that cancers diagnosed before age 50 now account for 6.1% of all colorectal cancers, with incidence rising by about 0.5% each year. The study highlighted higher rates of rectal and right‑sided colon cancers in young women and a larger share of metastatic disease at diagnosis (28% vs. 20% in older patients). Researchers link the trend to diet high in processed foods, obesity, sedentary lifestyles, and microbiome changes.

Health officials urge young adults to watch for warning signs such as persistent changes in bowel habits, rectal bleeding, unexplained anemia or weight loss, and to discuss screening with their physicians, especially if a relative has had polyps or cancer.