For decades flexible colonoscopy has been the gold standard for screening asymptomatic adults for colon and rectal cancers. While there was some reduction in mortality from colon cancer with the use of older tests for the presence of occult blood in the stool, experts generally believed that colonoscopy was a better test.
In recent years a new test has come on the market and will soon replace the old hemoccult test. It is called the FIT test, or fecal immunochemical test. It is much more sensitive and specific than the older hemocuult test. So the question now beomes: since the FIT test is so much better do we need to continue to perform flexble colonoscopy? The Dutch have attempted to answer this question.
The Dutch have conducted a clinical trial to determine what is the optimal strategy to prevent premature death from colon and rectual cancer. Click here to see the results of their actual study, published in the Annals of Internal Medicine. They use a risk-adjusted model to determine when their citizens need their next colonoscopy, e.g., if you had large colon polyps detected at your initial screening, you would get your next screening much sooner than if you did not. They then subdivided their population so more people got just the FIT test, some got both FIT and colonoscopy, and some got neither. To reduce a complicated trial design to easy-to-comprehend results, what the Dutch found was that the FIT test reduced mortality from CRC by 50% and that the further addition of colonoscopy added only 2% to that figure.
Are these results applicable the the American situation? This isn’t entirely clear. They are provocative, however, and suggest that the better we get at the non-invasive screening for colorectal cancer, the more likely we will be able to eliminate screening colonoscopy completely.