This week’s New England Journal of Medicine includes a study from Norway on efficacy of colonoscopy. The conclusions aren’t necessarily applicable to colorectal cancer screening in the U.S.
Here are a few issues to keep in mind when reading the study and talking with your patients:
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This study shows that colonoscopy screening IS effective – if it is completed.
Only 42% of patients randomized to colonoscopy completed the test. Among patients who actually got the colonoscopy, results are much more impressive in CRC prevention (31% decrease) and mortality (50% decrease). These data show that colonoscopy is effective if it is completed.
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Quality matters.
In this study, many endoscopists had ADRs below the 25% benchmark. We know that low ADRs are associated with a higher risk of post-colonoscopy CRC.
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The benefits of colonoscopy take time.
Detection and removal of polyps prevent future cancers. If we assume that the “usual care” patients had a similar rate of pre-cancerous polyps that are not removed, it will take time before they develop CRC. Hence differences between the two groups may increase with longer follow-up, which is planned.
Talking points for your patients:
If you know your adenoma detection rate, compare it to the rates of the doctors in the study.
Thanks to AGA President John Carethers and David Lieberman, chair of the AGA Executive Committee on the Screening Continuum, for his comments on this study. Read more about AGA’s CRC task force and our call for a national screening program.