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 pan-chromoendoscopy 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 (ACN) 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 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 odds ratio OR, 2.36; 95% CI, 1.29–4.33). Detection of proximal SLs was associated with synchronous ACN (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. Trial registration: UMIN-CTR number, UMIN 000042890