Do Not Skip Your Colonoscopy: Here’s Why

By Dr. Gregory Lam


If you had the opportunity to improve your chances of living without cancer, would you take that opportunity?

A recent study in the New England Journal of Medicine, “Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death,” was sensationalized in the news media to demonstrate that colonoscopies may not be as effective as once thought. However, looking more closely, this study actually demonstrates a colonoscopy is effective and remains the gold standard for colon cancer prevention.

Effect of Colonoscopy

The NordICC study involved 84,585 participants from Norway, Sweden, and Poland drawn from population registries from 2009 to 2014. This population was then randomized to receive either an invitation to undergo screening colonoscopy or no invitation to undergo screening.

This newly published study then followed the participants over a median follow-up of 10 years after enrollment, to gauge the percentage who developed colorectal cancer. It was found that there was an 18% risk reduction of colon cancer incidence and no reduction in colon cancer mortality in the patient population which was invited to undergo screening.

This was picked up by several news agencies that colon cancer screening programs may not be as effective as once thought. However, there were several aspects of this study that were not explained initially.

For starters, only 42% of the population that was invited to undergo colonoscopy did so. When looking at the people who did get a colonoscopy, there was a 31% decrease in the risk of colorectal cancer and a 50% decrease in risk of colorectal cancer-related death. This means a colonoscopy is only effective when it is performed.

“I don’t think anyone should be cancelling their colonoscopy,” Dr. Jason Dominitz, director of gastroenterology at the Veterans Health Administration, told CNN Health. “We know that colon cancer screening works.”

Colon Cancer Screening in the U.S.

  • Colonoscopies save lives. Previous studies in the U.S. and even this latest one in Europe have demonstrated the significant benefit of colonoscopies in reducing colorectal cancer mortality.
  • A colonoscopy prevents cancer with hard evidence. Of all screening modalities, colonoscopy is the only test that enables a medical professional to fully evaluate the colon and remove precancerous polyps at the same time.
  • Colorectal cancer grows very slowly. It can take a non-cancerous polyp many years to form into cancer. The full benefits may be outside the 10-year window that this study examined.
  • U.S. Gastroenterologists have high standards. The American College of Gastroenterology and American Society for Gastrointestinal Endoscopy has very high standards for quality colonoscopy which Cincinnati GI physicians adhere to. The average adenoma detection rate in the US is 39%. Almost one-third of the endoscopists in the NEJM study had an adenoma detection rate below the minimum threshold of 25%.
  • Geography and lifestyle matters. The study of populations in Norway, Poland, and Sweden, may not be representative of the diverse populations we have in the U.S., and particularly in Cincinnati.

Fact: Colonoscopies Remain the Best Option

Colorectal cancer is the third most common cancer diagnosed in the United States. The American Cancer Society estimates 151,030 new colorectal cancer cases in 2022. It is thought that due to colon cancer screening there has been a downward trend of incidence rates in older adults. However, there has been a rising rate among younger patients.

The U.S. Preventive Services Task Force recently recommended that average-risk Americans begin screening for colon cancer at age 45 rather than 50. Colonoscopy saves lives. It screens, detects, and prevents colorectal cancer.

Many variables, such as family history and race, put some people at higher risk of colorectal cancer than others. However, we agree that the timing of a colonoscopy can depend on certain guidelines. If you’re unsure of when to get the procedure, we will talk it through with you, candidly. Contact us, here.

You can learn more about colon cancers here. To read about advancements (and myths) in colonoscopy preparation, read our blog on the topic.