What is time interval between two consecutive colon cancer screenings? Is it best to alternate virtual colonoscopy with flexible sigmoidoscopy for colorectal cancer screening? What to do if a small polyp is found during colonoscopy? Leading virtual colonoscopy screening expert discusses CT colonography. Virtual colonoscopy.

Screening for colon cancer. Dr. Anton Titov, MD. What is your current recommendation for the best method and frequency of screening for colorectal cancer? There are fecal occult blood tests, colonoscopy, CT colonography. Dr. Perry Pickhardt, MD. We look at the colon cancer screening purely from a health risk perspective. We do not consider the government funding or the cost perspective. Dr. Anton Titov, MD. What is the age when someone should consider doing the first colonoscopy? What affects the frequency of screening for colon cancer? This is a very important topic, obviously. But if we are simply to consider patient outcomes and population health, it is clearly better to do a preventive test. The colon cancer screening test that can find polyps before they become colorectal cancer. Fecal sample-based tests are not the answer. Dr. Perry Pickhardt, MD. Fecal occult blood testing, stool DNA testing unfortunately simply do not do a good enough job to detect these advanced adenomas. Fecal occult blood testing does not find large polyps. Whereas with the preventive test does find large polyps. We have optical colonoscopy and CT colonography. CT colonography is the preferred test. Because it has a nice balance between accuracy for detecting the important lesions. Dr. Perry Pickhardt, MD. But virtual colonocopy leaves behind the tiny diminutive colon polyps that really need not be removed. Virtual colonoscopy can screen for the important precancerous colon lesions in a safer and cheaper way. Dr. Anton Titov, MD. It is more effective method than optical colonoscopy. CT colonography is a better, faster, safer, cheaper colon cancer screening method. CT colonography does so with the prevention benefit that both colonoscopy and CT colonography have. Sometimes optical colonoscopy is negative. It can be done at a 10 year intervals currently. However, it is very uncommon for many doctors not to find a tiny polyp during colonoscopy. Dr. Perry Pickhardt, MD. Patients receive recommendation to repeat colonoscopy at sooner intervals. Many patients are disappointed that they often don't get the full 10 year interval between colonoscopies as is usually recommended. For CT colonography, we started out at a 5 year interval colon cancer screenings. We thought we didn't have enough data. We thought maybe virtual colonoscopy accuracy was closer to the barium enema. We're finding that we could probably expand interval between successive tests. 5 to 10 years is probably the appropriate interval between two CT colonography tests. Dr. Perry Pickhardt, MD. But virtual colonoscopy is still such a relatively new colon cancer screening test. We are currently saying "5 years for the first follow up". After that you may continue to have a negative result. Then it is 10 years thereafter. Then once you reach the age of 80 to 85, then it becomes individualized whether or not you really need to continue screening. Dr. Anton Titov, MD. At that point, many people can probably discontinue routine screening for colon cancer.