Cancer Research

Single Colonoscopy Cuts Colorectal Cancer Risk 19% Over 13 Years But Misses Mortality Target

The NordICC randomized trial followed over 84,000 Europeans for 13 years to assess whether a single colonoscopy screening reduces colorectal cancer incidence and death. Those invited to screening had a 19% lower risk of developing colorectal cancer compared to the unscreened group. Among those who actually completed the colonoscopy, the benefit was even greater — a 45% reduction in incidence. However, colonoscopy screening did not significantly reduce colorectal cancer mortality at 13 years. Notably, cancer death rates in both groups were far lower than originally projected when the trial was designed, suggesting broader improvements in colorectal cancer treatment over time. Benefits were stronger for distal colon cancers and in men compared to women.