Bretthauer · The New England journal of medicine 2022 · pragmatic randomized controlled trial · n=84585

Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death.

Cited 805 times in the scientific literature.

Level 2 - randomized trial

Pragmatic randomized controlled trial

PubMed 36214590 · doi:10.1056/NEJMoa2208375 · record verified 2026-08-30

What was done

Presumptively healthy adults aged 55 to 64 from population registries in Poland, Norway, Sweden, and the Netherlands (enrolled 2009–2014) were randomly assigned 1:2 to receive either an invitation for a single screening colonoscopy (invited group) or usual care without screening invitation. Primary endpoints were 10-year risks of colorectal cancer and colorectal cancer-related death; the secondary endpoint was all-cause mortality.

What was found

Among 84,585 participants with follow-up in Poland, Norway, and Sweden (28,220 invited, 56,365 usual care), 42.0% (11,843) of invited participants underwent colonoscopy. Over a median 10-year follow-up, colorectal cancer incidence was 0.98% (259 cases) in the invited group versus 1.20% (622 cases) in the usual-care group (risk ratio 0.82; 95% CI, 0.70 to 0.93; number needed to invite: 455). Colorectal cancer mortality was 0.28% in the invited group versus 0.31% in the usual-care group (risk ratio 0.90; 95% CI, 0.64 to 1.16). All-cause mortality was 11.03% versus 11.04% (risk ratio 0.99; 95% CI, 0.96 to 1.04). Major bleeding occurred in 15 participants after polyp removal; no perforations or 30-day screening-related deaths occurred.

Why it matters

This pragmatic trial provides long-term randomized evidence on population-level colonoscopy screening invitations, showing a modest reduction in colorectal cancer incidence but no significant decrease in colorectal cancer mortality at 10 years.

Limits

Adherence to the screening invitation was low (42.0%), which substantially attenuates the intention-to-screen effect estimates. The 10-year follow-up window may be insufficient to detect a mortality benefit given the slow progression of colorectal cancer. Follow-up data were not reported for the Netherlands cohort.

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