Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death
- Study type
- Clinical trial
- Study name
- NordICC
- Design
- Pragmatic randomised trial with a 1:2 allocation ratio; intention-to-screen analysis
- Sample size
- 84,585 participants with follow-up data (Poland, Norway and Sweden): 28,220 in the invited group and 56,365 in the usual-care group
- Source
- N Engl J Med · 2022
- Trial registration
- NCT00883792
In plain words
In this study, people aged 55 to 64 were randomly either invited to have one screening colonoscopy or not invited at all. About 42% of those invited actually had the colonoscopy. After 10 years, bowel (colorectal) cancer was found less often in the invited group (0.98% vs 1.20%). But over this time no clear difference was seen in deaths from this cancer or deaths from any cause. Serious complications of colonoscopy were rare, but major bleeding after polyp removal occurred in 15 people.
Key results
Treatment arms and regimens
Received an invitation to undergo a single screening colonoscopy. Of the 28,220 people in this group, 11,843 (42.0%) were screened.
No invitation and no screening (56,365 people).
Source of the regimen details: Abstract of the paper (screening intervention; no drug or dose involved)
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Presumptively healthy men and women aged 55 to 64, identified from population registries in Poland, Norway, Sweden and the Netherlands between 2009 and 2014. Follow-up data were available for participants in Poland, Norway and Sweden.
Endpoints
Primary endpoints: risk of colorectal cancer and risk of related death. Secondary endpoint: death from any cause.
Safety and side effects
15 participants had major bleeding after polyp removal. No perforations or screening-related deaths occurred within 30 days after colonoscopy.
Clinical significance and place in guidelines
This randomised trial showed that an invitation to a single screening colonoscopy reduces the 10-year risk of colorectal cancer (an 18% reduction in the intention-to-screen analysis). At 10-year follow-up, a significant reduction in colorectal cancer death was not shown. The abstract gives no information on changes to clinical guidelines or regulatory approvals; the place of these findings in current guidelines should be checked separately and interpreted by the treating physician.
Limitations
Only 42.0% of the invited group were actually screened, and the reported results are by intention to screen. The 95% CI for the risk ratio of colorectal cancer death (0.64 to 1.16) includes 1. Follow-up data were available only for participants in Poland, Norway and Sweden. The secondary outcome of death from any cause also showed no difference.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.