Response to NEJM study on colonoscopies

When you read beyond the headlines, it’s clear colonoscopies do save lives.

Published on October 13, 2022

A recent study from the New England Journal of Medicine spurred headlines that colonoscopies are not as effective at preventing colorectal cancer deaths as previously thought. But while this headline may grab your attention, it is also misleading. The fact remains: colonoscopies save lives.  


Michael Bretthauer, M.D., Ph.D., and colleagues at the University of Oslo and Oslo University Hospital in Norway conducted a clinical trial of more than 80,000 people ages 55-64 in Poland, Norway and Sweden. About 28,000 of the participants were randomly selected to receive an invitation to get a one-time screening colonoscopy, while the rest did not.  

The results:

Bretthauer’s analysis that colonoscopies underperformed (18% reduction in colorectal cancer cases and no significant reduction in mortality) does not tell the whole story. His results were based on the entire study population—but critically, only 42% of those invited to screen completed a colonoscopy.  

When looking at the segment of study participants who got a colonoscopy, 31% had pre-cancerous adenomatous polyps removed, preventing potential cancers from occurring. In that same group, there was a 50% reduction in mortality.  

The study also only followed participants for 10 years; we may see even stronger results (fewer cancer cases and deaths) over a longer time.  

What this all means:

Nothing about this study changes the fact that colonoscopies—and other types of colorectal cancer screenings—save lives. Colonoscopies are an important tool in preventing colorectal cancer (by finding and removing polyps) and in detecting it early, when treatment is more likely to be successful.  

What you should do:

The Prevent Cancer Foundation continues to advocate for people ages 45-75 at average risk* to get routine colorectal cancer screenings. If you’re at increased risk, you may need to start regular screening at an earlier age and/or be screened more often. There are several options available for colorectal cancer screening—talk with your health care provider about which screening is right for you.  

Screening should continue through age 75 if you are in good health, with a life expectancy of 10 years or more. If you are age 76–85, talk with your health care provider about whether to continue screening. After age 85, you should not get screened. 

Learn more:  

Colorectal cancer prevention, screening and early detection 

Too Young for This Sh*t: colorectal cancer in young adults 

Fact Check: Do Colonoscopies Save Lives? From our friends at Fight Colorectal Cancer and Colon Cancer Coalition.  

* ‘Average risk’ means you do not have:  

  • A personal history of inflammatory bowel disease (such as ulcerative colitis or Crohn’s disease). 
  • A personal history of colorectal cancer or certain kinds of polyps (“flat polyps”).  
  • A family history of colorectal cancer.  
  • Hereditary colorectal cancer syndrome (such as familial adenomatous polyposis (FAP) or Lynch syndrome). 

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