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Does a Colonoscopy Help Detect Cancer? A New Study Says No, But Doctors Disagree

October 11, 2022

A new study in the New England Journal of Medicine says colonoscopies are less effective than originally thought in detecting cancer. But don’t cancel this standard screening tool just yet. Hartford HealthCare experts warn that the Norwegian research is dangerously flawed. > Schedule my colonoscopy

Flawed research

“The European study had many flaws, including the fact that only 42% of those offered a colonoscopy actually received one,” noted Jeffry Nestler, MD, chief of gastroenterology at Hartford Hospital. Anant Agarwalla, MD, another Hartford HealthCare gastroenterologist, agreed, saying, “This study shows that colonoscopies don’t do anything if you don’t get them.” Of the 42% of study participants who got a colonoscopy, the procedure reduced the risk of colon cancer by 31% and the risk of dying by colon cancer by half. In addition, Dr. Agarwalla said flaws included:
  • Sidestepping some of the unique features of the American population, especially in communities of color where rates of colorectal cancer and related deaths are higher.
  • Low quality ratings for the gastroenterologists following study participants. The average rating was about 25%, while the average in American gastroenterologists is about 40%.
  • Only following the patients for 10 years, when the advantage of colonoscopy is helping to prevent cancer years later.
“This study reemphasized the importance of colonoscopy as an effective test, and that not getting one is not going to help prevent colon cancer,” Dr. Agarwalla said. > Want more health news? Text StartHere to 85209 to sign up for text alerts

Bottom line

“The results support the fact that if you do not get a screening colonoscopy, there will be little benefit on reducing colon cancer,” Dr. Nestler said, adding that he does not expect any change in federal recommendations for screening colonoscopy based on this study. Guidelines currently urge anyone over the age of 45 to have a screening colonoscopy. Earlier screening is suggested in those having a family history of colorectal cancer. “Colonoscopy remains the gold standard for detecting and preventing colon cancer. We know first-hand that it saves lives. It’s the only test that screens, prevents and detects,” Dr. Agarwalla said.

Hartford HealthCare Cancer Institute