Effect of colonoscopy screening on risks of colorectal cancer and related death.

Bretthauer M, Loberg M, Wieszcy P, Kalager M, Emilsson L, Garborg K et al, for the NordICC Study Group.

N Engl J Med 2022; 387: 1547-1556.

This study included over 84,000 people aged 55 to 64. A single colonoscopy reduced the risk of colorectal cancer by 18% after 10 years (number needed to screen to prevent one colorectal cancer = 455). The risk of death from colorectal cancer and the overall risk of death was not significantly reduced by screening.

Comment: As is so often the case with screening programmes, they can be shown to reduce the rate of the specific condition, but not mortality.