Which Fecal Immunochemical Test Should I Choose?

Abstract

Objectives: To summarize the fecal immunochemical tests (FITs) available in the United States, the 2014 pathology proficiency testing (PT) program FIT results, and the literature related to the test characteristics of FITs available in the United States to detect advanced adenomatous polyps (AAP) and/or colorectal cancer (CRC). Methods: Detailed review of the Food and Drug Administration’s Clinical Laboratory Improvement Amendments (CLIA) database of fecal occult blood tests, the 2014 FIT PT program results, and the literature related to FIT accuracy. Results: A search of the CLIA database identified 65 FITs, with 26 FITs available for purchase in the United States. Thirteen of these FITs were evaluated on a regular basis by PT programs, with an overall sensitivity of 99.1% and specificity of 99.2% for samples spiked with hemoglobin. Automated FITs had better sensitivity and specificity than CLIA-waived FITs for detection of AAP and CRC in human studies using colonoscopy as the gold standard. Conclusion: Although many FITs are available in the United States, few have been tested in proficiency testing programs. Even fewer have data in humans on sensitivity and specificity for AAP or CRC. Our review indicates that automated FITs have the best test characteristics for AAP and CRC.

Positive predictive values of fecal immunochemical tests used in the STOP CRC pragmatic trial

“…The sample available in this study was small; future studies of larger representative samples are needed for confirmation and improved precision of estimates. In vitro spike‐in proficiency tests have demonstrated high sensitivity and specificity (all ≥93%) for hemoglobin in all three tests used in our study; however, such tightly controlled studies may not translate into similarly high‐performance characteristics in real‐world settings of variable sample preparation, handling, and analysis. Our analysis represents real‐world performance of the FITs that clinics chose to use, and results are intended to inform future FIT choices and the comparative cost‐effectiveness of each.…”

Colorectal cancer screening for average‐risk adults: 2018 guideline update from the American Cancer Society

“…However, most brands of FIT have limited evidence demonstrating their accuracy for detection of CRC. Daly et al found published data from colonoscopy‐confirmed studies of FIT performance for only 6 of the 26 versions of FIT sold in the United States . Because studies have shown variable performance of different FITs across studies in which individuals undergo multiple tests to compare outcomes, it should not be assumed that versions of FIT that lack published data have suitable performance characteristics …”

“…Daly et al found published data from colonoscopyconfirmed studies of FIT performance for only 6 of the 26 versions of FIT sold in the United States. 113 Because studies have shown variable performance of different FITs across studies in which individuals undergo multiple tests to compare outcomes, [114][115][116] it should not be assumed that versions of FIT that lack published data have suitable performance characteristics. 117 The original, low-sensitivity guaiac tests have largely been superseded by HSgFOBT and FIT in organized screening programs around the world, and a similar shift is underway in the United States.…”

Faecal immunochemical tests for haemoglobin (FIT) in the assessment of patients with lower abdominal symptoms: current controversies

“…Although there are a large number of qualitative 15 and qualitative 16 FIT available, it could be argued that the available evidence suggests that both qualitative and quantitative FIT appear to give somewhat similar clinical outcomes 10 and both could be used in assessment of patients presenting with lower abdominal symptoms if the disadvantages of the two rather different approaches were carefully kept in mind.…”