Colorectal cancer is one of the very few cancers that can be prevented by removing polyps or other precancerous growths and can be cured if detected early. In fact, when detected and treated early, the five-year relative survival rate of colorectal cancer is 90%.
Fortunately, there are a number of tests available for prevention and early detection of colorectal cancer and precancerous polyps, which include a barium enema, fecal occult blood test, and colonoscopy. Recently, a newer and less invasive test, known as virtual colonoscopy (VC) or CT colonography, has been added to the recommended list.
Virtual colonoscopy uses x-rays and computers to produce two- and three-dimensional images of the colon (or large intestine) to diagnose colon and bowel disease. There are several advantages to a VC exam. For instance, it is more comfortable than conventional colonoscopy because it does not require inserting a camera-tipped tube rectally. As a result, patients do not need to be sedated and can quickly return to a normal, daily routine after the exam. The procedure also provides clearer, more detailed images than conventional x-rays by using a barium enema. Last, the exam takes less time than a conventional colonoscopy or a lower gastrointestinal series.
Still, there are some disadvantages to a VC. Tissue samples or polyps cannot be taken or removed during the procedure, and a conventional colonoscopy must be performed if abnormalities are found. In addition, VC does not show as much detail as a conventional colonoscopy, so polyps smaller than 10 millimeters in diameter may not show up on the images. VC may also fail to detect lesions that are flat, a form that has been reported to be especially risky and more common in the United States than previously realized.
AFCR encourages both men and women, beginning at age 50, to schedule a colonoscopy exam or other screening tests to help screen for cancerous and precancerous lesions . Talk to your doctor about which type of colorectal exams is right for you.
