Don’t Cancel Your Colonoscopy

While a recent study published in the New England Journal of Medicine is being used by some to suggest that colonoscopies are overrated as a cancer screening and prevention tool, experts urge you not to cancel your colonoscopy appointment. These colorectal cancer experts and advocacy organizations are questioning the interpretation of the study and reaffirming the importance of screening.

The Northern-European Initiative on Colorectal Cancer (NordICC) study was a randomized trial involving men and women ages 55 to 64 years in Poland, Norway, Sweden, and the Netherlands. Participants were randomly assigned to one of two groups. The “invited group” received an invitation for a colonoscopy, while the “usual-care group” did not. The screenings took place between 2009 and 2014.

The study authors concluded that the risk of colorectal cancer after 10 years was lower in the “invited group” but said the risk reduction was a mere 18%. However, experts who were not involved note that more than half of the group invited to receive a colonoscopy never showed up for the procedure, which lessens the apparent benefit of the procedure because the results include those people too.

“Only 42% of the patients in the screening arm of the NordICC study actually underwent the offered one-time colonoscopy,” said Reid M. Ness, MD, MPH, associate professor of medicine at Vanderbilt University Medical Center. “Although the authors report little or no benefit to their offer of screening, the numbers improve substantially when you consider only those who actually had a colonoscopy performed.”

Colonoscopies Prevent Deaths

While there may have been an 18% reduction among all the patients in the screening-invitation group, Dr. Ness explained that the data for the participants who actually received a colonoscopy shows a 31% reduction in colorectal cancer risk. There was also a 50% decrease in colorectal cancer-related deaths over the 10 years of the study.

“Colonoscopy can only be beneficial if you actually have it performed,” said Dr. Ness.

Colorectal cancer advocacy groups are sharing a similar message. “It is important to remember that the population from this trial is a sample of patients from Poland, Norway, Sweden, and the Netherlands, but is by no means an exhaustive sample,” said Anjee Davis, Fight Colorectal Cancer (Fight CRC) President. “Also, only 42% of study participants invited to undergo a colonoscopy actually completed the screening.”

Also, colonoscopy isn’t the only type of colon cancer screening test available. “Numerous studies have underscored that when patients are given a choice, they are more compliant and willing to be screened,” Davis continued. “There isn’t a silver bullet screening test. But if a patient completes a screening test that they choose, screening for colorectal cancer will save lives: That’s the message that needs to be heard.”

The Expertise of the Endoscopist Matters

Some experts also question the caliber of the endoscopists who helped with the study. An endoscopist is a doctor or other medical professional who is trained to use an endoscope – a long, thin, flexible tube inserted through the rectum to view the colon, rectum, and digestive tract. The skill level of an endoscopist is based on a number called the adenoma detection rate (ADR). The ADR represents how often they detect precancerous polyps during colonoscopies. The higher the ADR, the better the endoscopist.

“The effectiveness of colonoscopy is dependent on both the skill and attentiveness of the endoscopist performing the procedure,” said Dr. Ness. “The best measure of these traits is the adenoma detection rate. Studies have shown that for every 1% increase in ADR for a given endoscopist, there is an associated 3% decrease in colorectal cancer cases and a 5% decrease in colorectal cancer deaths among that provider’s patients. The authors report that 29% of the study endoscopists had ADRs less than the recommended minimum threshold of 25%. This means that almost a third of the endoscopists in this study would be considered inadequate by current practice standards in the United States.”

Four Things You Should Know

As experts question the results of the study, some media outlets are using it to challenge the importance of screening. If you have questions about the benefits of colonoscopies, talk to your doctor. Don’t let media headlines impact your healthcare decisions. Here are four things you should know:

1. Colorectal cancer is common. According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in the United States, excluding skin cancers.

2. Colonoscopies are effective. “A colonoscopy is an effective tool for the prevention of colorectal cancer and colorectal cancer-related death when you have it performed by an endoscopist who performs quality colonoscopy as evidenced by an adequate ADR,” said Dr. Ness.

3. Colonoscopies provide long-term benefits. “Colorectal cancers (CRCs) are thought to arise from pre-existing polyps that require 10 to 30 years to become cancer,” said Dr. Ness. “Thus, we would expect to see greater improvements in CRC outcomes over time and would anticipate the outcomes in the screening arm of this study to likewise improve in the future.”

4. This study does not contradict the United States Preventive Services Task Force recommendation that adults ages 45 to 75 get screened for colorectal cancer. “In reality, the study illustrates the opposite,” said Dr. Ness. “It shows that colonoscopy is very beneficial if you actually have it performed.”

For questions about your colorectal cancer risk and how often you should get screened, talk to your doctor.