From the Guidelines
I strongly recommend using liquid-based FIT every 2 years for average-risk individuals as part of routine colorectal cancer screening, as it has been shown to be an effective method for detecting hidden blood in stool and reducing CRC mortality 1. The test requires collecting a small stool sample using a provided brush or stick, which is then placed in a collection tube containing a stabilizing buffer solution. This liquid preservation method improves sample stability and allows for more accurate results compared to older guaiac-based tests. Some key points to consider when using liquid-based FIT include:
- The test has several advantages, including requiring only one stool sample, having no dietary restrictions, and offering better detection of early cancers and advanced adenomas 1.
- If the FIT result is positive, a follow-up colonoscopy is necessary to investigate the source of bleeding.
- The test works by using antibodies that specifically detect human hemoglobin in stool, making it more sensitive and specific for lower gastrointestinal bleeding than older testing methods 1. It is essential to follow the kit instructions precisely, avoid collecting samples during menstruation or if you have active hemorrhoids, and return the sample within the timeframe specified (typically within 7 days). The American College of Physicians recommends selecting the colorectal cancer screening test with the patient on the basis of a discussion of benefits, harms, costs, availability, frequency, and patient preferences, and suggests screening tests and intervals such as fecal immunochemical testing or high-sensitivity guaiac-based fecal occult blood testing every 2 years 1.
From the Research
FIT Test Liquid Based
- The Fecal Immunochemical Test (FIT) is a screening test for colorectal cancer that detects blood in the stool 2, 3, 4.
- FIT is recommended as a first-tier test for colorectal cancer screening, along with colonoscopy, due to its high sensitivity and specificity 2.
- The test is typically performed annually, and individuals with a positive result are referred for colonoscopy 5.
- Studies have shown that FIT is effective in reducing mortality from colorectal cancer, with a sensitivity of 32% for advanced colonic neoplasia 6.
- FIT is preferred over fecal occult blood testing (FOBT) due to its higher sensitivity and specificity 6.
- The test is also less invasive and more convenient than colonoscopy, making it a popular choice for individuals who are average-risk for colorectal cancer 4.
- However, FIT may not detect all cases of colorectal cancer, and individuals with a family history of the disease or other risk factors may require more frequent or invasive screening 3.