Colon cancer is the third leading cause of cancer death in the United States. It is estimated that 134,000 individuals will be diagnosed with colon cancer in 2016 and about 49,000 will lose their lives to the disease. Although anyone at any age can develop colon cancer, it is most commonly diagnosed among adults between the ages of 65 to 74 years of age.
There are several screening methods for colon cancer, but the gold standard of colon screening is the colonoscopy. A colonoscopy allows your doctor to view the entire length of your colon to evaluate the health of your digestive tract. Using a long, flexible tube called a colonoscope, your doctor will insert the tube into your rectum. A camera attached to the tube will help your doctor see any abnormalities
This single test offers three distinct benefits: detection, treatment and prevention.
- Detection--Instead of taking an image of your colon, your doctor is visualizing and examining the lining of your colon with a scope to find abnormalities.
- Treatment—If abnormalities like lesions or polyps are discovered, they can be removed and/or sent to a pathology laboratory for evaluation.
- Prevention—With regular colonoscopies, precancerous polyps do not have the opportunity to develop into cancerous growths because they are removed before they become a health concern.
This third benefit—prevention—makes colonoscopies distinct among other screenings. Periodically, the U.S. Preventative Services Task Force (USPSTF) reviews the effectiveness of health screenings that are offered to Americans. The USPSTF also reviews the evidence on effectiveness of screening with colonoscopy, flexible sigmoidoscopy, computed tomography colonography, fecal occult blood test, immunochemical test, and several other tests in:
- reducing the incidence and mortality from colon cancer
- the harms of the screening tests
- how well the tests detect adenomatous polyps
- how well the tests detect colon cancer
The USPSTF also commissioned a study to provide information on the optimal starting and stopping ages and screening intervals among the available screening methods. The recommended starting age for a colonoscopy is still 50 years of age, and the recommended stopping age remains at 75 years of age. The interval between tests remains unchanged at 10 years between exams, unless a doctor recommends a different interval.
Although there are many tests that detect the presence of an abnormality in the colon, a colonoscopy is the only test that offers the benefits of detection, treatment and prevention. Because it is the most thorough and comprehensive test, it is more invasive than a stool sample or CT image. The invasiveness of the colonoscopy is a significant deterrent to many patients, so the USPSTF concludes that “The best test is the test that gets done.” However, a colonoscopy has the ability to detect colon cancer in the early stages, and colon cancer is most easily treated when discovered early.