Colonoscopy conversion after flexible sigmoidoscopy screening: results from the UK Bowel Scope Screening Programme.

Area of Science:

• Gastroenterology
• Public Health
• Oncology

Background:

• The UK Bowel Scope Screening Programme (BSSP) uses flexible sigmoidoscopy (FS) to identify high-risk patients for subsequent colonoscopy.
• Assessing the effectiveness of colonoscopy conversion criteria and identifying predictors of additional adenoma detection is crucial for optimizing screening pathways.

Purpose of the Study:

• To evaluate the practice of colonoscopy conversion following FS within the BSSP.
• To identify predictors for the detection of additional adenomas during colonoscopy after initial FS.

Main Methods:

• A retrospective analysis of the Bowel Cancer Screening database, including endoscopic and histological findings from patients undergoing colonoscopy post-FS (August 2013 - August 2016).
• Multivariate analysis was employed to determine predictors of new adenoma detection.

Main Results:

• Out of 11,711 FS procedures, 421 (3.6%) converted to colonoscopy with an additional adenoma detection rate (ADR) of 35.2%.
• Male gender and polyps ≥10mm detected during FS were significant predictors of additional adenomas (≥10mm) found during colonoscopy.
• Villous histology, polyp size ≥10mm, and male gender predicted new adenomas ≥10mm; any conversion criterion predicted proximal adenomas and those ≥10mm.

Conclusions:

• Male gender, larger polyps (≥10mm), and villous histology during FS are key predictors for adenomas found during subsequent colonoscopy.
• Further research is needed to explore gender-based stratification of colonoscopy conversion criteria in screening programs.