Faecal immunochemical tests versus colonoscopy for post-polypectomy surveillance: an accuracy, acceptability and...

Area of Science:

• Gastroenterology
• Oncology
• Health Economics

Background:

• Patients at intermediate risk for colorectal cancer (CRC) in the UK undergo surveillance colonoscopy 3 years post-polypectomy.
• Colonoscopy surveillance is associated with costs, patient discomfort, and a small risk of complications.

Purpose of the Study:

• To evaluate the effectiveness, acceptability, and cost-saving potential of annual fecal immunochemical tests (FITs) compared to colonoscopy for detecting CRC and advanced adenomas (AAs).

Main Methods:

• A diagnostic accuracy study incorporating health psychology assessment and economic evaluation.
• Participants (aged 60-72) at intermediate CRC risk received quantitative FITs annually for 3 years post-polypectomy.
• Positive FIT results led to colonoscopy referral; negative results allowed continued FIT surveillance with a 3-year colonoscopy.

Main Results:

• Annual FITs with colonoscopy referral for positive cases were more cost-effective than 3-yearly colonoscopies.
• Sensitivity for CRC detection was high with annual FITs, particularly at lower thresholds (e.g., 84.6% at 10 µg/g over three rounds).
• However, FIT surveillance could miss a significant proportion of AAs (40-70%) and some CRCs (15-30%) at higher thresholds.

Conclusions:

• Annual low-threshold FIT with selective colonoscopy offers a cost-saving surveillance strategy with high CRC sensitivity.
• This approach may miss a substantial number of advanced adenomas.
• Most participants preferred annual FITs combined with 3-yearly colonoscopies, indicating a need for further research to define optimal FIT surveillance roles.