As a primary care physician, I have long been an advocate of colonoscopy for colorectal cancer screening in my patients. So, I read with interest a recent publication in the New England Journal of Medicine that assessed the effects of colonoscopy screening on the risks of colorectal cancer and related death. For some, the results at first seemed confusing as they seemed to question the magnitude of the benefits of recommending a screening colonoscopy.
The confusion resulted from the study design, which compared research participants who were invited to get a screening colonoscopy to those who were not. Unfortunately, a significant number of those participants invited to undergo the screening procedure chose not to have it done. This was a large study conducted in Europe, where screening colonoscopy is less common than in the United States.
The most important take-away from this recent study is that screening colonoscopy only prevents and detects colon cancer if it is done. The study showed that among those who completed the procedure, colon cancer risk was reduced by over 30% and death from colon cancer was decreased by about 50%, consistent with other studies.
Colorectal cancer is among the leading causes of cancer death in both men and women. Currently, the U.S. Preventive Services Task Force recommends routine screening for all people ages 45 to 75 years. People ages 76 to 85 years and those with a family history of colon cancer are advised to consult with their physician regarding screening recommendations.
The Task Force recommends several options for colorectal cancer screening, including stool testing, flexible sigmoidoscopy, colonoscopy and CT colonography (or so-called virtual colonoscopy). The best screening method is the one that a person is willing to complete.
That said, full colonoscopy offers several advantages. It permits visualization of the entire colon, not just the portion near the rectum known as the sigmoid colon. It also permits the identification and removal of colon polyps, which have the potential to develop into colon cancer. In this way, it is not just a screen for early or asymptomatic cancer that has already developed but it is also a preventive measure by removing so-called adenomatous polyps, which could later develop into a cancer.
Colon polyps are relatively common in older people, and the benefits of screening colonoscopy to remove these polyps before they can become a cancer is likely the reason why studies have shown that colonoscopy prevents colon cancer and related deaths.
The COVID-19 pandemic has had many indirect effects on health and preventive health care. If you are older than 45 and have not had screening for colon cancer, now is a good time to talk to your doctor about the best screening strategy for you. Odds are that your doctor will recommend a colonoscopy.
Dr. Matthew A. Clark, a board-certified physician in internal medicine and pediatrics, works for the Indian Health Service.
