While FIT is an important screening tool for colorectal cancer (CRC), the disparagement of colonoscopy is unwarranted. CRC incidence has declined by 30% between 2000 and 2010, and the widespread use of colonoscopy is a major factor in this decline. When FIT is positive, patients must undergo colonoscopy, or the initial test is useless.
Dr. Krist states colonoscopy is not better than FIT. Colonoscopy rarely misses CRC, detects more than 90% of large precancerous polyps, and is the best test for detecting serrated lesions, which account for 25% of CRCs. FIT misses 20% of CRCs, 70% of large precancerous polyps, and detects no serrated lesions.
Kaiser operates organized screening programs, where all persons are mailed FIT kits, and navigators assist patients through screening. Such resources are not available in most of the U.S. making adherence to annual FIT problematic.
It is true that other countries often use FIT as a preferred CRC screening tool. These countries often have fewer resources, and they have not seen the same reductions in CRC incidence documented in the U.S.
Klaus Mergener, MD, PhD, MBA
President, American Society for Gastrointestinal Endoscopy
Douglas K. Rex, MD
President-Elect, American Society for Gastrointestinal Endoscopy