Virtual or Real, Colonoscopy Is Best
Study Shows Both Types Are More Accurate Than Other Colon Cancer Screenings
WebMD News Archive
Colonoscopies, Real and Virtual, Outperform Other Tests
The study, presented at the annual Gastrointestinal Cancers Symposium, involved 307 men and women aged 50 or older. None had symptoms of colon cancer.
After stool samples were collected for FIT and FOBT testing, the patients underwent colonoscopy and CTC on the same day. By counting lesions found in the lower third of the colon in a colonoscopy, the researchers could approximate the results of sigmoidoscopy.
Results showed that colonoscopy and virtual colonoscopy detected advanced adenomas -- growths destined to become cancers -- at nearly the same rate. They also detected polyps larger than 10 millimeters -- a size considered dangerous -- at basically the same rate. Colonoscopy found far more tiny polyps -- 5 millimeters or smaller -- than did CTC. But such polyps only rarely turn cancerous.
Sigmoidoscopy, on the other hand, only found about two-thirds of colon growths. FIT detected fewer than half of growths, while FOBT only found about one-fifth.
FOBT gave false-positive results to 10% of people who didn't have the dangerous growths. The comparable figure for FIT testing was 14%.
Kolligs says that combining the results of various tests -- sigmoidoscopy plus FOBT, sigmoidoscopy plus FIT, and FOBT plus FIT -- resulted in "no or only slightly increased rates of detection over one test alone."
Schilsky says that while his institution has virtual reality as an option for patients who might prefer not have a colonoscopy, he still recommends his patients have the real thing. The reason, he tells WebMD, is that any polyps that are found via colonoscopy can be immediately removed. Patients who have suspicious polyps found by CTC must still undergo colonoscopy to have them taken out.