Patients Prefer More Invasive Form of Colon Scan: Study
TUESDAY May 22, 2012 -- Patients undergoing colonoscopies frequently complain about having the procedure, which involves threading a camera through the colon to detect precancerous or cancerous growths.
But a new study has found that patients overwhelmingly preferred colonoscopy to the less invasive and less time-consuming CT-based colon scan.
Colonoscopy has long been the standard of care for colon cancer screening. Computed tomography (CT) colonography -- sometimes called "virtual colonoscopy" -- is a newer technology and involves simply scanning the abdomen to look for abnormalities.
Colon cancer is one of the most common cancers in the world but can largely be prevented with adequate screening.
For this study, 90 patients at average risk for colon cancer underwent CT colonography followed by a colonoscopy within the following two hours. They then answered 13 questions regarding their experience.
All participants underwent the same preparation for the procedure, involving drinking copious amounts of liquid the night before to clean out the bowel.
Three-quarters of the patients said they would opt for a traditional colonoscopy for their next examination.
The remaining one-quarter who preferred CT colonography said they did so because it took less time -- 10 minutes versus about 30 minutes for colonoscopy.
"Overall, patients would prefer colonoscopy for a repeat procedure," said Dr. Greg Rosenfeld, co-author of the study, which is being presented Tuesday at Digestive Disease Week meetings in San Diego.
Specifically, participants reported less anxiety and pain with a colonoscopy, as well as a slight preference for the endoscopy unit (used for colonoscopy) versus the radiation suite (used for CT colonography).
Rosenfeld, of the University of British Columbia in Vancouver, said the researchers were a "little bit surprised" by the findings, but attribute them to the fact that patients reported less pain with the colonoscopy.
Patients received mild sedation and were conscious during the colonoscopy. No sedation or painkiller was given for the CT colonography, which involves distending the stomach with carbon dioxide.
A second study presented at the conference found that patients' perception of the preparation required for a colonoscopy (often cited as onerous and uncomfortable) affected not only how clean the colon was but also how accurately polyps and adenomas were detected.
For this study, 430 patients undergoing colonoscopy completed an 18-point questionnaire regarding how clean their bowel was and other aspects of their experience with the procedure.
There was a correlation between how well the bowel was prepared and both how clean the bowel was at the time of the colonoscopy and how many adenomas were found.
"How many adenomas we found is directly associated with how many cancers develop and how many lives we could save," said study lead author Dr. Edward Holt, a gastroenterology fellow with California Pacific Medical Center in San Francisco.
After adjusting for various factors, women were found to be, overall, less satisfied with the experience. It's not clear why, but the fact that women are more likely than men to have irritable bowel syndrome may be related, Holt said.
Because the studies were presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
The U.S. National Cancer Institute has more on colorectal cancer.
Posted: May 2012
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