# Effect of colonoscopy screening on risks of colorectal cancer and related death (NordICC)

Source: https://onco.cc/key-papers/paper-bretthauer-nordicc-colonoscopy-screening-nejm-2022/  
OnCo record `paper-bretthauer-nordicc-colonoscopy-screening-nejm-2022` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The first randomised trial of screening colonoscopy itself. Inviting people to one colonoscopy cut bowel cancer cases by 18 percent over ten years, less than expected, largely because only 42 percent of those invited turned up.

## Summary

Bretthauer, Løberg, Wieszczy and colleagues ran a pragmatic randomised trial in presumptively healthy men and women aged 55 to 64, drawn from population registries in Poland, Norway, Sweden and the Netherlands between 2009 and 2014, assigning them 1:2 either to an invitation to a single screening colonoscopy or to no invitation. The primary end points were the risks of colorectal cancer and related death; the secondary end point was death from any cause.

Follow-up data were available for 84,585 participants in Poland, Norway and Sweden: 28,220 invited, of whom 11,843 (42.0 percent) underwent screening, and 56,365 in usual care. Fifteen participants had major bleeding after polyp removal, and there were no perforations or screening-related deaths within 30 days.

## Fields

- Kind: Key paper
- Last checked: 2026-09-24
- Tags: colorectal-evidence
- Journal: New England Journal of Medicine
- Year: 2022
- DOI: 10.1056/NEJMoa2208375
- Authors: Bretthauer M, Løberg M, Wieszczy P, et al.
- Findings: Over a median ten years, 259 colorectal cancers in the invited group against 622 in usual care.; Ten-year colorectal cancer risk 0.98 percent invited against 1.20 percent usual care: an 18 percent reduction (risk ratio 0.82, 95 percent CI 0.70 to 0.93).; Risk of death from colorectal cancer 0.28 percent against 0.31 percent (risk ratio 0.90, 95 percent CI 0.64 to 1.16).; Number needed to invite to prevent one cancer: 455 (95 percent CI 270 to 1,429).; All-cause mortality 11.03 percent against 11.04 percent (risk ratio 0.99).
- What it means: Colonoscopy screening works, but the effect a health system gets is the effect of the invitation, not of the procedure; uptake, not test performance, is the binding constraint, and this is the trial that made that argument unavoidable.
- Caveats: Only 42 percent of those invited attended; per-protocol estimates of the effect in those screened are larger but no longer randomised.; Ten years is short for a cancer-prevention endpoint, and the mortality confidence interval crosses 1.; Adenoma detection rates varied widely between the participating endoscopists.

## Sources

- N Engl J Med 2022: https://doi.org/10.1056/NEJMoa2208375
- PubMed: https://pubmed.ncbi.nlm.nih.gov/36214590/

## Connected records

- key papers: [Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths (National Polyp Study)](https://onco.cc/key-papers/paper-zauber-national-polyp-study-colonoscopic-polypectomy-nejm-2012/), [Multitarget stool DNA testing for colorectal-cancer screening](https://onco.cc/key-papers/paper-imperiale-multitarget-stool-dna-screening-nejm-2014/), [Quality indicators for colonoscopy and the risk of interval cancer](https://onco.cc/key-papers/paper-kaminski-adenoma-detection-rate-interval-cancer-nejm-2010/)
- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/)
- fronts: [Early Detection & Screening](https://onco.cc/fronts/early-detection/), [Prevention & Risk](https://onco.cc/fronts/prevention/)
- terms: [Colonoscopy](https://onco.cc/terms/colonoscopy/), [Endoscopy (EGD, EUS, ERCP)](https://onco.cc/terms/endoscopy/)
- technologies: [Colorectal cancer screening (colonoscopy, FIT, stool DNA, blood)](https://onco.cc/technologies/colorectal-screening/)
- trials: [NordICC (Nordic-European Initiative on Colorectal Cancer)](https://onco.cc/trials/nordicc/)
- people: [Michael Bretthauer](https://onco.cc/people/michael-bretthauer/)
- bottlenecks: [Overdiagnosis and false alarms](https://onco.cc/bottlenecks/b-overdiagnosis/), [Prevention we already have is not deployed](https://onco.cc/bottlenecks/b-prevention-adoption/), [The hardest cancers are found late](https://onco.cc/bottlenecks/b-early-detection/)
- journals: [New England Journal of Medicine](https://onco.cc/journals/nejm/)
- roadmaps: [Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation](https://onco.cc/roadmaps/colorectal-roadmap/)
- ideas: [Treat screening uptake, not test sensitivity, as the thing to optimise, and settle the age extension with a trial rather than a model](https://onco.cc/ideas/idea-crc-screening-uptake-and-age-extension/), [UK gap: match endoscopy capacity and quality to the faecal immunochemical test thresholds the NHS has already set](https://onco.cc/ideas/idea-crc-uk-colonoscopy-capacity-and-fit-threshold/)

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