Risk of missing colorectal cancer with a COVID-adapted diagnostic pathway using quantitative faecal immunochemical...

Area of Science:

• Oncology
• Diagnostic Imaging
• Gastroenterology

Background:

• COVID-19 presented challenges to healthcare services, necessitating adapted diagnostic pathways.
• Suspected bowel cancer diagnostics were adapted using quantitative faecal immunochemical tests (qFITs) and CT mini-prep.

Purpose of the Study:

• To estimate risk mitigation and residual risk of undiagnosed colorectal cancer.
• To evaluate a COVID-adapted pathway combining qFITs and CT mini-prep for suspected bowel cancer.

Main Methods:

• Decision-tree models were developed using pathway data, local qFIT audit data, literature, and expert opinion.
• Diagnostic scenarios included single qFIT, dual qFIT, qFIT with CT mini-prep, and dual qFIT with CT mini-prep.
• These were compared against standard colonoscopy or CT virtual colonoscopy (CTVC) pathways.

Main Results:

• A single qFIT triage test risked missing 20.2% of colorectal cancers.
• A dual qFIT and CT mini-prep approach reduced missed cancer risk to 6.49%.
• The enriched pathway increased colonoscopy/CTVC rates from 287 to 418 per 1000 patients.

Conclusions:

• Triage with qFIT alone risks a high rate of missed colorectal cancers.
• CT mini-prep as an add-on test can reduce this risk for triage to colonoscopy or CTVC.