Colonoscopy Test for Colon Cancer May Be More Effective
Although there is no dispute that people over age 50 should be screened for colon cancer, the medical community has been split over which methods are best. In addition to barium enemas and colonoscopies, other recommended screening tests for colon cancer include a fecal occult test, which can detect blood in the stool, and sigmoidoscopy, which is less invasive than a colonoscopy.
The study by Winawer and his colleagues is the first to match one method against the other to see which is better at detecting polyps. The researchers performed both barium enemas and colonoscopies on more than 500 people, and also reviewed the findings on more than 300 other people who had only colonoscopies. All the patients previously had polyps. Colonoscopies found three times as many smaller polyps and twice as many larger ones as barium enemas did.
"With colonoscopy, the potential implication for saving lives is exceptional," says Winawer, who maintains that the overall costs of all screening techniques are about equal. "With the rising costs of cancer care, screening is becoming cost-saving."
Several colon cancer experts tell WebMD the study findings are welcome confirmation of how they already have been practicing.
"To my knowledge this is this the largest, if not the only, comparison of these two [methods], and the results are impressive. Most people have already been favoring colonoscopy to barium enema, and this adds credibility to that behavior," says Neal Meropol, MD, who reviewed the study for WebMD. Though the findings aren't surprising, he says, the data from earlier studies were not definitive. Meropol is director of gastroenterology cancer programs at Fox Chase Cancer Center in Philadelphia.
Meropol also sees a broader application to the findings, noting that the various medical societies should revisit their recommendations about which method is preferred for colon cancer screening and follow-up.
David A. Rothenberger, MD, said further study is needed before colonoscopy becomes the gold standard for colon cancer screening, although he says it is essential for patients who require follow-up.
"Increasingly, people are demanding the 'Katie Couric approach,' even as a first-time screening test," says Rothenberger, a clinical professor and chief of the Division of Colon and Rectal Surgery at the University of Minnesota, and director of cancer programs there.