A new correspondence published in The Lancet contends that the results of the NordICC trial, which evaluated the effects of a one-time screening colonoscopy offer, should be interpreted against the backdrop of widespread colonoscopy use in routine clinical practice during the study period. The letter, responding to the trial's 13-year follow-up findings, notes that the estimated reductions in colorectal cancer incidence and mortality were substantially lower than what researchers had anticipated when the trial was designed.
The NordICC trial, led by Michal F. Kaminski and colleagues, offered a single screening colonoscopy to participants aged 55 to 64 and tracked outcomes over 13 years. The correspondence does not dispute the trial's data but places the findings in a broader context: because colonoscopy was already widely used in clinical practice during the trial era, the incremental benefit of offering one additional screening colonoscopy may have been diluted. This, the authors suggest, helps explain why the observed reductions fell short of original projections.
Colorectal cancer remains one of the most common and deadly cancers worldwide, and screening is a cornerstone of prevention efforts. Colonoscopy is considered the gold standard for detecting and removing precancerous polyps, but its effectiveness as a population-level screening tool has been debated, particularly regarding how much it reduces cancer incidence and mortality when offered broadly. The NordICC trial was designed to provide rigorous evidence on this question, and its results have prompted significant discussion among clinicians, researchers, and public health officials.
The correspondence emphasizes that the trial's findings should not be read as a dismissal of colonoscopy's value. Rather, they highlight the complexity of evaluating screening programs in settings where the procedure is already accessible. In such contexts, the additional benefit of a single invitation may appear modest, even if colonoscopy remains effective for individuals who undergo it. The authors also point out that the trial's design—a one-time offer rather than a sustained screening program—may limit how directly its results can be applied to real-world screening recommendations.
These observations come at a time when health systems are increasingly focused on optimizing cancer screening strategies, balancing effectiveness, cost, and patient burden. The NordICC trial's 13-year follow-up provides valuable long-term data, but the correspondence argues that its implications for policy and practice must be weighed carefully. The lower-than-expected reductions in incidence and mortality underscore the need for continued research into how best to implement and evaluate colorectal cancer screening, including the role of colonoscopy alongside other methods such as stool-based tests.
For clinicians and patients, the key takeaway is that screening decisions should remain individualized, informed by the best available evidence. The correspondence does not call for abandoning colonoscopy but rather for a nuanced interpretation of the NordICC results. As the medical community continues to debate the optimal approach to colorectal cancer prevention, the trial and the ensuing discussion will likely shape future guidelines and research priorities.
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