High Detection Rates and Associated Factors of Colorectal Serrated Lesions: A Multicenter Prospective Study in the Asia-Pacific.

Introduction: Colorectal serrated lesions (SLs) are recognized as precursors of colorectal cancer (CRC); however, their detection rates and prevalence remain inadequately defined. We aimed to assess their detection rates and estimate their prevalence in the Asia-Pacific, as well as to examine their associated factors.

Methods: This was a multicenter prospective study in the Asia-Pacific. Asymptomatic individuals aged 40-74 years undergoing first-time colonoscopy for CRC screening were prospectively enrolled. To ensure precise prevalence estimates, colonoscopy procedures involved repeated proximal colon inspection using panchromoendoscopy with indigo carmine dye. Detection rates of proximal SLs and sessile serrated lesions (SSLs) were calculated. Mixed-effects logistic regression analyses, accounting for institution-level variability, were performed to identify factors associated with proximal SL and SSL detection. Associations between SLs and synchronous advanced colorectal neoplasia were evaluated.

Results: Among 965 participants, detection rates of proximal SLs and SSLs were 16.1% (95% confidence interval [CI], 13.8-18.5) and 8.6% (6.9-10.6), respectively. Institutional differences affected detection of proximal SLs (adjusted median odds ratio [OR], 1.44; 95% CI, 1.25-1.79) and SSLs (1.34; 1.18-1.62). A family history of CRC was associated with higher SSL detection (adjusted OR, 2.36; 95% CI, 1.29-4.33). Detection of proximal SLs was associated with synchronous advanced colorectal neoplasia (OR, 1.94; 95% CI, 1.24-3.02 and 1.90; 1.18-3.07, respectively).

Discussion: This multicenter study demonstrates that detection rates and estimated prevalence of SLs are higher than previously reported in the Asia-Pacific and highlights the impact of institutional differences, challenging the notion of their low regional prevalence.