article316

NordICC

"Clinical Effectiveness of Colonoscopy Screening in Reducing Colorectal Cancer Risk".The New England Journal of Medicine. 2022.ClinicalTrials.gov number, NCT00883792.

Clinical Question

Does an invitation to undergo a single screening colonoscopy reduce the risk of colorectal cancer and related death in a healthy population aged 55 to 64?

Bottom Line

Invitation to undergo a single screening colonoscopy in a population-based randomized trial was associated with an 18% reduced risk of colorectal cancer over 10 years compared to no screening intervention, although participation was 42%.

Major Points

Guidelines

There are currently no updated guidelines incorporating the results of this trial.

Design

Multicenter, pragmatic, randomized controlled trial with participants randomized in a 1:2 ratio to receive an invitation to a single screening colonoscopy (invited group) or no invitation (usual-care group).

Population

84,585 participants aged 55 to 64, drawn from population registries in Poland, Norway, and Sweden.

Interventions

42% of the invited group underwent screening colonoscopy.

Outcomes

Primary outcomes:
- Risk of colorectal cancer after 10 years was 0.98% in the invited group vs. 1.20% in the usual-care group (risk reduction of 18%, risk ratio 0.82; 95% CI, 0.70 to 0.93).
- Risk of death from colorectal cancer was 0.28% in the invited group vs. 0.31% in the usual-care group (risk ratio 0.90; 95% CI, 0.64 to 1.16).

Secondary outcome:
- Risk of death from any cause was similar in both groups (11.03% invited vs. 11.04% usual-care; risk ratio 0.99; 95% CI, 0.96 to 1.04).

Criticisms

- Lower than expected participation rate in colonoscopy screening.
- The study did not capture the effect of adherence to follow-up recommendations for polyp surveillance.
- Additional analyses are required for assessments related to distal vs. proximal cancers, sex, and age-related differences.

Funding

Research grants from the Research Council of Norway and others, bowel preparation from Dr. Falk Pharma, grants from National Center for Research and Development of Poland, and other national grant agencies.