YouTubing

YouTubing

A friend of mine named Charles (who’s nearing his 60th birthday) recently mentioned that he’s planning his second tubing expedition.

“Tubing” is his metaphor for “colonoscopy.” When you allow doctors to sedate you and insert a camera where no ray of sunshine ever falls, it helps to have a sense of humor about it.

But according to a new study, Charles may not need to go tubing because a tube-free method might work just as well. No tube sounds promising, but is this alternative screening technique really preferable?

Double jeopardy

For more than three decades, optical colonoscopy (OC) has been the primary method of colon cancer screening. But an alternative method called computed tomographic colonography (CTC) has been developed over the past few years. This method is also known as “virtual colonoscopy” because it’s minimally invasive, requiring a catheter to be inserted into the rectum to fill the colon with air, followed by noninvasive optical scan.

Obviously neither method is a day at the beach, but is CTC as effective as OC? That’s the question researchers at the University of Wisconsin Medical School set out to answer with a study that was published earlier this month in the New England Journal of Medicine.

STUDY PROFILE

• The UW team compared screening results from 3,163 patients who underwent traditional colonoscopy to the results from 3,120 patients who were examined with the CTC technique
• In the CTC screening, 123 advanced tumors were found, compared to 121 in the OC group
• Total polyps removed in the CTC group: 561
• Total polyps removed in the OC group: 2,434
• Seven perforations of the colon occurred in the OC group compared to none in the CTC group

Researchers concluded: “These findings support the use of CTC as a primary screening test before therapeutic OC.”

The risk of a perforated colon is a clear drawback for traditional colonoscopy, but let’s take another look at two of those bullet points regarding the total polyps removed. Those numbers are so lopsided because all polyps are routinely removed on the spot during OC, but when polyps were detected in the CTC group, patients were given the option of leaving very small polyps in place or undergoing an additional OC procedure to remove the polyps.

Tiny polyps may never become a problem, but with OC there’s no question – the polyps are removed. And this is a clear advantage of traditional colonoscopy. In the UW study, about eight percent of the patients underwent follow-up OC after undergoing CTC.

Balloon animal

Virtual colonoscopy is generally referred to as “noninvasive.” But as noted above, there’s an invasive moment when air is pumped into the colon by catheter. Given the choice between air and a tube, most people would probably choose air. But I know of at least one patient who wouldn’t recommend filling the colon with air.

In an e-Alert I sent you about two years ago, an HSI member shared a friend’s account of a CTC procedure: “I thought I was going to just have a CT scan. NO, NO. You have to pump yourself up with air so that they can take the pictures. Filling yourself up with air is undescribable. I thought I was going to blow off the gurney. It takes 7 minutes all told but it was the longest 7 minutes I have ever gone through.

“It has been one week since the test and my stomach is still very large and hard. I am sure that there is still air in there. God knows how long this lasts. It also makes it difficult to eat as you feel full very quickly. So all I can say is never, never again would I do this.”

Now that I’ve completely scared everyone away from considering CTC, it should be noted that this procedure may have an unexpected benefit that OC doesn’t provide. According to a HealthDay report about a 2005 study of 500 patients who underwent CTC, in more than half the cases doctors discovered other health issues that were unrelated to the colon – problems such as lesions, masses in solid organs, and large aneurysms.

If you’re due for a colon screening, talk to your doctor about the pros and cons of the CTC and OC techniques. But keep in mind that OC is relatively new, so it’s not yet covered by most insurance plans.

Sources:
“CT Colonography Versus Colonoscopy for the Detection of Advanced Neoplasia” New England Journal of Medicine, Vol. 357, No. 14, 10/4/07, content.nejm.org