Wall Street Journal
Two Studies Recommend Less-Frequent
By WILLIAM M. BULKELEY
September 23, 2008
Two new large medical studies recommend less frequent and less invasive colon exams for most people over 50.
The studies both appeared in this week's New England Journal of Medicine. One found that a less invasive procedure, called computed tomographic, or CT, scans are as effective in detecting pre-cancerous growths as optical colonoscopies, in which a probe is inserted into the rectum. The computerized scans cost about half as much as a colonoscopy and don't involve sedation.
Both processes do require bowel preparation by taking strong laxatives, which many patients find the worst part of the screening.
The second study, which involved 1,256 patients who had tested
negative for growths, found that five years later, none of the
patients had developed colon cancer. The study leader, Dr.
Thomas Imperiale of Indiana University School of Medicine in
It isn't clear how much the studies will affect clinical practice. Some medical groups already recommend either CT scans or colonoscopy as the best way to detect pre-cancerous growths, but many doctors push patients toward colonoscopies. Both tests are considered much more accurate than less expensive techniques like blood tests. Many doctors and Medicare currently recommend rescreening for healthy patients every 10 years.
Robert H. Fletcher, professor emeritus at
The study of CT scans collected data on 2,531 patients at 15
study centers around the country. All of them were tested with
both a CT scan and a colonoscopy. The scan picked up all but 10%
of the large growths that were found with the colonoscopy.
That's equivalent to the accuracy of colonoscopies, as
determined by previous studies. Daniel Johnson, chairman of the
radiology department at Mayo Clinic,
He noted that most patients prefer CT scans because "you don't get sedated and you can go back to work" that day. In addition, he said, a CT scan costs about $600 to $1,200, which is about half the amount widely charged for a colonoscopy. He predicts that if more doctors begin to recommend CT scans, more people will get screened.
Write to William M. Bulkeley at firstname.lastname@example.org