Long-term performance of colorectal cancerscreening programmes based on the faecal immunochemical test

Area of Science:

• Gastroenterology
• Oncology
• Public Health

Background:

• Long-term performance of colorectal cancer (CRC) screening using 2-year fecal immunochemical tests (FIT) remains unclear.
• Evaluating the efficacy of repeated FIT screening is crucial for optimizing CRC detection strategies.

Purpose of the Study:

• To assess the long-term performance of repeated FIT screening for colorectal cancer.
• To examine FIT positivity rates, detection rates for CRC and advanced adenomas, and positive predictive values (PPV) over multiple screening rounds.
• To determine the cumulative detection rates of CRC and advanced adenomas after five rounds of FIT screening.

Main Methods:

• A cohort of 50-69 year olds underwent repeated FIT screening (OC-Hemodia latex agglutination test; cut-off: 20 µg Hb/g faeces) over 12 years (2002-2014).
• Analysis included FIT positivity, CRC and advanced adenoma detection rates, and PPV at each screening round.
• Cumulative detection rates after five rounds were calculated.

Main Results:

• Over 123,347 individuals were screened up to six times, diagnosing 781 CRCs and 4713 advanced adenomas.
• CRC and advanced adenoma detection rates declined substantially after the first few rounds but then stabilized.
• The PPV for advanced neoplasia decreased in the second round and remained stable thereafter, correlating with a declining FIT positivity rate.

Conclusions:

• Repeated FIT screening effectively reduces colorectal disease burden and optimizes colonoscopy resource allocation.
• The cumulative detection rate after five FIT rounds is comparable to primary colonoscopy screening.
• It is essential to consider the cumulative sensitivity of repeated FIT when evaluating its overall efficacy in CRC screening programs.