Easier, Safer Colon Cancer Test?
Cutting-Edge Technologies Promise Less Discomfort, More Accurate Results
May 18, 2004 (New Orleans) -- Perhaps no medical test is more dreaded than the colonoscopy, but cutting-edge technologies promise not only less discomfort, but also more accurate results and, possibly, less frequent screenings.
"Colonoscopies are one of the most feared screening tests," Bernard Levin, MD, vice president for cancer prevention at the M.D. Anderson Cancer Center of the University of Texas in Houston, tells WebMD. "There's a sense of invasion into a part of the body that people generally don't want to talk about. Anything that makes it easier, safer, and more comfortable would be a real advance."
During a colonoscopy, a long, flexible, lighted tube is snaked up through the rectum and into the colon to look for early signs of cancer. Caught early, abnormal growths can be removed, preventing full-blown cancer, Levin notes. Yet some studies estimate that as many as 50% of people who should be undergoing colonoscopy shun the procedure.
Enter some of the novel technologies discussed here this week at Digestive Disease Week, a major medical meeting of gastroenterologists:
Video Pill Catches Cancerous Growths
A vitamin-sized pill that houses technology similar to a digital camera may some day prove a reliable alternative to conventional colonoscopy, British researchers report.
Known as the M2A Capsule Endoscopy, the video pill is already being used to diagnose unexplained bleeding, Crohn's disease, and other abnormalities of the small bowel and intestine. But getting it to quickly propel further down the gastrointestinal tract to the much larger colon has proved a challenge.
"We thought, wouldn't it be great if you could just swallow a pill and get images of the colon?" says Paul Swain, MD, professor of gastrointestinal endoscopy at London University in England. "But by the time it got to the colon, the batteries ran out."
So his team modified the device, either using twice as many batteries or a delayed mode that offered a few hours of extra time.
The results "were astonishing," Swain tells WebMD.
In a study of 14 patients who had bleeding that the doctors thought came from the colon, the pill found abnormal growths that signal an increased risk of cancer or cancer itself in nine instances.
"We found all the pathology there was," he says. "The rest of the patients proved to have bleeding due to other causes, such as a small ulcer that healed on its own."
Traditional colonoscopy can miss about 10% of abnormal growths, while Swain estimates that the pill "probably misses as many as 20%."
But, he explains, "The pill can reach places a scope can't."
There are other advantages, too. Encased in a white plastic capsule, the camera can capture tens of thousands of images as it propels itself down the esophagus and stomach, through the small intestine, and into the colon.