# NordICC: inviting people to a screening colonoscopy reduced bowel cancer, but less than expected

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

## TL;DR

NordICC, the first randomised trial of colonoscopy screening, invited 84,585 people aged 55 to 64 to a single colonoscopy or to no screening. Bowel cancer incidence fell 18% over ten years among those invited, but only 42% attended, and the fall in bowel cancer deaths did not reach statistical significance, fuelling debate over colonoscopy versus stool-test programmes.

## Summary

NordICC randomised 84,585 people aged 55-64 in Poland, Norway and Sweden to an invitation to a single screening colonoscopy or to usual care with no screening. The primary endpoints were colorectal cancer incidence and death at 10 years, analysed by intention to screen.

The 10-year risk of colorectal cancer was 0.98% in the invited group and 1.20% in usual care (risk ratio 0.82). Colorectal cancer death was 0.28% versus 0.31%, not significantly different. In the adjusted per-protocol analysis, assuming everyone invited had attended, incidence fell 31% and death 50%.

The trial prompted a wide debate about the real-world effect of colonoscopy programmes versus stool-test programmes.

## Fields

- Kind: Key paper
- Last checked: 2026-09-08
- Journal: New England Journal of Medicine
- Year: 2022
- DOI: 10.1056/NEJMoa2208375
- Authors: Bretthauer M, Løberg M, Wieszczy P, et al.
- Findings: Colorectal cancer incidence at 10 years: 0.98% vs 1.20% (RR 0.82, 95% CI 0.70-0.93) by intention to screen; Colorectal cancer death: 0.28% vs 0.31% (RR 0.90, 95% CI 0.64-1.16); Only 42% of those invited underwent colonoscopy; Adjusted per-protocol estimate: incidence RR 0.69, death RR 0.50 among those who attended; Number needed to invite to prevent one cancer over 10 years: 455
- What it means: A colonoscopy probably does reduce bowel cancer risk for the person who has it, but a programme that offers colonoscopy achieves much less if most people decline. Programmes based on stool tests with high uptake may deliver as much population benefit at lower cost and risk.
- Caveats: Low participation dilutes the intention-to-screen effect; the per-protocol estimate relies on modelling assumptions; Ten years is short for a mortality endpoint after polyp removal; a 15-year analysis is planned; Adenoma detection rates varied between endoscopists and some were below quality thresholds; Results apply to a one-off colonoscopy at 55-64, not to repeated colonoscopy programmes as practised in the US

## Sources

- DOI: https://doi.org/10.1056/NEJMoa2208375
- ClinicalTrials.gov NCT00883792: https://clinicaltrials.gov/study/NCT00883792
- 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/), [Minnesota trial: a yearly stool blood test cuts bowel cancer deaths by a third](https://onco.cc/key-papers/paper-minnesota-fobt-nejm-1993/), [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/)
- ideas: [Personalised stool-test cut-offs by age, sex and prior results](https://onco.cc/ideas/idea-prev-fit-risk-adapted-thresholds/), [Send screening invitations with a pre-booked time, not a request to call](https://onco.cc/ideas/idea-prev-screening-default-appointments/), [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/)
- 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/)
- technologies: [Colorectal cancer screening (colonoscopy, FIT, stool DNA, blood)](https://onco.cc/technologies/colorectal-screening/)
- terms: [Colonoscopy](https://onco.cc/terms/colonoscopy/), [Endoscopy (EGD, EUS, ERCP)](https://onco.cc/terms/endoscopy/), [Faecal immunochemical test (FIT)](https://onco.cc/terms/fit-test/)
- 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/)

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