‘Virtual’ Test Effective for Some at High Risk

“Virtual colonoscopy” detects colon cancer well in some high-risk people, a new study has found. The test’s formal name is computed tomographic (CT) colonography. It uses X-rays to look for colon cancer. The study included 937 people. They received a CT colonography test and a colonoscopy on the same day. Colonoscopy uses an instrument that is inserted into the colon. It’s considered the best test for colon cancer. CT colonography found 85% of the cancers that the colonoscopy found. It was effective for people at high risk because of colon polyps or a family history of colon cancer. But the CT test had a 15% “false positive” rate for people who were labeled high risk because they had blood in their stool. For these people, the test said they had cancer, but they did not. The study was published in the Journal of the American Medical Association.