From the Guidelines
Your Fecal Immunochemical Test (FIT) result is negative, which is good news, indicating a lower risk for colorectal cancer or significant colorectal disease, and no immediate follow-up testing is needed based on this negative result alone. This means that no blood was detected in your stool sample. However, it's essential to continue with routine colorectal cancer screening according to your healthcare provider's recommendations, which typically means repeating the FIT test annually if you're at average risk 1. The FIT test is the primary test of choice for population-based CRC screening programmes in resource-limited countries, as stated in the joint Asian Pacific Association of Gastroenterology (APAGE)-Asian Pacific Society of Digestive Endoscopy (APSDE) clinical practice guidelines 1.
Remember that while this negative result is reassuring, it's not a guarantee against colorectal cancer. The FIT test specifically looks for hidden blood in the stool, which can be an early sign of colorectal polyps or cancer. If you develop concerning symptoms such as persistent changes in bowel habits, rectal bleeding, abdominal pain, or unexplained weight loss, contact your healthcare provider promptly regardless of this negative test result. It's also important to note that the use of FIT in screening for advanced or non-advanced adenomas is not recommended due to its limited diagnostic accuracy 1. Additionally, caution should be practiced when interpreting FIT results in certain individuals, such as males, those with a family history of CRC, smokers, and users of aspirin or non-steroidal anti-inflammatory agents 1.
According to the US Preventive Services Task Force recommendation statement, screening with annual FIT provides an estimated greater life-years gained than annual high-sensitivity gFOBT or sDNA-FIT every 3 years 1. Therefore, repeating the FIT test annually is a reasonable approach for average-risk individuals, but it's crucial to follow your healthcare provider's specific recommendations.
From the Research
Fecal Immunochemical Test (FIT) Overview
- The Fecal Immunochemical Test (FIT) is a screening tool used for colorectal cancer (CRC) detection 2, 3, 4, 5, 6.
- FIT has a high sensitivity for detecting CRC, especially in symptomatic populations 5.
- The test can be used as a qualitative or quantitative test, with better sensitivity for hemoglobin than older guaiac fecal occult blood tests 6.
FIT Performance and Accuracy
- Studies have shown that FIT has a modest sensitivity for advanced neoplasia, ranging from 20% to 33.1% 2, 3.
- The specificity of FIT is generally high, ranging from 89% to 93% 2, 3.
- Factors associated with false-positive and false-negative FIT results include age, smoking, and use of aspirin/nonsteroidal anti-inflammatory drugs 3.
Comparison with Colonoscopy
- FIT has been compared to colonoscopy in several studies, with results showing that repeated FIT screening can be equivalent to colonoscopy in detecting advanced neoplasia 4.
- FIT may be a useful tool for populations where compliance with colonoscopy is low 4.
Clinical Guidelines and Recommendations
- The Association of Coloproctology of Great Britain and Ireland and the British Society of Gastroenterology have developed guidelines for the use of FIT in the diagnostic pathway of people with signs or symptoms of suspected CRC 5.
- The guidelines recommend using FIT as an objective measure of risk, with a high positive predictive value for CRC, to identify patients who require colorectal investigation with the highest priority 5.