# Michael Bretthauer

Source: https://onco.cc/people/michael-bretthauer/  
OnCo record `michael-bretthauer` (Person). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Led NordICC, the first randomised trial of screening colonoscopy, which found smaller benefits than many expected.

## Summary

Michael Bretthauer (University of Oslo) was principal investigator of NordICC, the Nordic and Polish randomised trial of invitation to screening colonoscopy, whose 2022 result of an 18% reduction in colorectal cancer incidence and no significant mortality benefit in the intention-to-screen analysis reset expectations for colonoscopy screening. He leads the Clinical Effectiveness Research Group and works on screening quality and trial methodology.

## Fields

- Kind: Person
- Last checked: 2026-09-10
- Tags: screening; colorectal; epidemiology
- Role: Professor of Medicine, University of Oslo; Gastroenterologist, Oslo University Hospital
- Specialisms: Colorectal cancer screening; Colonoscopy trials; Screening epidemiology

## Sources

- PubMed: https://pubmed.ncbi.nlm.nih.gov/?term=Bretthauer%20M%5BAuthor%5D%20colonoscopy%20screening

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Early-onset colorectal cancer (under 50)](https://onco.cc/cancers/early-onset-colorectal/)
- institutions: [Oslo University Hospital, The Norwegian Radium Hospital](https://onco.cc/institutions/oslo-radium-hospital/)
- key papers: [NordICC: inviting people to a screening colonoscopy reduced bowel cancer, but less than expected](https://onco.cc/key-papers/paper-nordicc-nejm-2022/)
- 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/)

---
JSON: https://onco.cc/api/v1/entities/michael-bretthauer.json