Why a colonoscopy is still the gold standard for preventing colon cancer

Prevent Colon Cancer: Have a colonoscopyI had my first colonoscopy at age 50, which is the current recommendation. My gastroenterologist, Dr. Douglas Howell, found a benign polyp and told me I was a poster child for colonoscopies. It’s why we do them, he exclaimed.

After two normal follow-up colonoscopies, a few weeks ago I had another and this time, he found two benign polyps. Before I headed home, I decided to interview my esteemed gastroenterologist for the sake of all of us.

Why should someone have a colonoscopy?

They’re important because virtually all colon cancers in our society come through first as benign polyps. Colonoscopy is not colon cancer detection, it’s actually colon cancer prevention. Patients who undergo removal of polyps are essentially then assured they will not develop colon cancer for a number of years. It’s very protective over a long period of time and that makes it a good buy.

Is colonoscopy the best way to detect polyps?

This is the current standard and I suspect it will remain so because it is preventive. Newer technologies have come along that are for detection of colon cancer. Unfortunately, those do not always detect colon cancer early and therefore not every patient will be cured. They also detect things that would require surgery to essentially cure. We would much rather prevent colon cancer from ever occurring and that’s the difference between the two sets of technologies.

Should everybody get a colonoscopy at age 50?

Everyone in our society should have their first colonoscopy at age 50 unless there is a family history. A first-degree relative raises the risk by at least three-fold and justifies beginning at age 40. If there’s anyone in the family who has had colon cancer younger than age 50 it may require very early screening or even genetic counseling because that may represent a very specific genetic risk. Ninety-five percent of colon cancer in our society, however, is sporadic and therefore 50 is the universal recommendation.

What have you learned after 30+ years of doing colonoscopies?

The national risk of colon cancer is about five percent. That’s one person in 20. Since all those patients virtually had polyps at some point, if polyps are detected at age 50 that triples the risk. About 30 percent of folks will have polyps at age 50. If you do the simple math, that isn’t a five percent risk. That’s going to be 15 or 20 percent, so a fair proportion of patients will have progressed to colon cancer.

There are other things that suggest higher risk — large polyps, multiple polyps, and polyps that grow back after a short period of time. There are a variety of ways we can customize the frequency with which the procedure needs to be done.

If the first exam at 50 is negative, we don’t recommend a repeat for 10 years. It’s very unusual in health maintenance to be able to go a full 10 years without having to worry about something.

The technology of colonoscopy has changed remarkably so we are more accurate in our recommendations. We now have high definition, we now have wide angle viewing, and we also use special counterstaining called chromoendoscopy. These features have greatly increased the accuracy and yield of colonoscopy so that when we make a recommendation we can be relatively certain it’s the correct recommendation for the person involved.

Dr. Douglas Howell, gastroenterologist, colonoscopy Dr. Douglas Howell is a gastroenterologist at Portland Gastroenterology in Portland, Maine. If you have any other questions (general questions, nothing personal) for Dr. Howell, let me know and I’ll ask.

Diane Atwood

About Diane Atwood

For more than 20 years, Diane was the health reporter on WCSH 6. Before that, a radiation therapist at Maine Medical Center and after, Manager of Marketing/PR at Mercy Hospital. Now she writes the award-winning blog Catching Health with Diane Atwood.