A major new study has found that colorectal cancer rates are rising again in the United States after more than two decades of steady decline, and the increase is no longer confined to younger adults. Researchers documented upticks across nearly every age group under 70, including older Americans who have historically benefited most from routine screening programs. The findings challenge long-held assumptions that improved testing and prevention would continue to drive rates downward, and they have left scientists uncertain about the underlying causes. Colorectal cancer remains among the most commonly diagnosed cancers in the country, making the reversal a significant public health concern.
Researchers are examining a range of possible explanations, from shifts in diet and lifestyle to environmental exposures and changes in screening behavior, but no single factor has been confirmed. The study's authors emphasized that the pattern is not limited to the well-publicized rise among adults in their 20s, 30s and 40s, which had already prompted updated screening guidelines. Health officials say the findings underscore the need for continued surveillance and research into why progress against the disease appears to be stalling. Further studies are expected to focus on identifying the drivers behind the trend and whether screening strategies should be adjusted in response.
Independent reporting synthesized from primary wires and global correspondents.