Navigating false-positive outcomes after stool-based colorectal cancer screening tests: a scoping review

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Colorectal cancer screening with stool tests can lead to positive results, necessitating colonoscopy.
• A negative colonoscopy after a positive stool test presents management challenges, particularly concerning potential extra-colonic cancers.

Purpose of the Study:

• To synthesize current clinical approaches and cancer outcomes after positive stool tests and negative colonoscopies.
• To identify research gaps in managing patients with positive stool tests and negative colonoscopies, especially regarding extra-colonic cancers.

Main Methods:

• A scoping review of English-language, peer-reviewed articles published up to September 2025.
• Two independent reviewers screened titles, abstracts, and full texts, extracting relevant data.
• Thematic synthesis explored outcomes and work-up strategies for false-positive stool tests (FIT, mt-sDNA) in extra-colonic cancer screening.

Main Results:

• Eight studies met inclusion criteria from 3442 identified.
• Demographic reporting was variable; most patients were female and over 50.
• Colorectal cancer (CRC) incidence was ~0.5% on second colonoscopy; extra-colonic aerodigestive/upper GI cancer incidence ranged from 0-4.3%.

Conclusions:

• Significant heterogeneity exists in reporting stool test positivity, negative colonoscopy definitions, and follow-up times.
• A standardized reporting framework is crucial for synthesizing study data.
• Improved standardization will enhance clinical management for patients with positive stool tests and negative colonoscopies.