Serrated Polyps and the Risk of Synchronous Colorectal Advanced Neoplasia: A Systematic Review and Meta-Analysis

Serrated polyps of the colon comprise a heterogeneous group of lesions with distinct histological and malignant features. The presence of serrated polyps has been associated with synchronous advanced neoplasia, although the magnitude of this relationship is unclear.Using studies identified from systematic literature search up to February 2014, we performed a systematic review and meta-analysis to estimate the pooled prevalence of serrated polyps and their association with synchronous advanced neoplasia. Random-effects models were used to combine estimates from heterogeneous studies, and odds ratios (ORs) with 95% confidence intervals (CIs) were presented.Nine studies with 34,084 participants were included. The mean age of subjects was 59.9±6.6 years and 52.5% of the subjects were male. Pooled prevalence of serrated polyps was 15.6% (95% CI, 10.3-22.9%). The pooled OR of advanced neoplasia in individuals with serrated polyps was 2.05 (95% CI, 1.38-3.04). Pooled analysis showed that the presence of proximal serrated polyps (OR=2.77, 95% CI, 1.71-4.46) and large serrated polyps (OR=4.10, 95% CI, 2.69-6.26) was associated with an increased risk of synchronous advanced neoplasia. The pooled OR for advanced neoplasia in individuals with proximal and large serrated polyps was 3.35 (95% CI, 2.51-4.46). Considerable heterogeneity was observed in most analyses.Our meta-analysis showed that serrated polyps are associated with a more than twofold increased risk of detection of synchronous advanced neoplasia. Individuals with proximal and large serrated polyps have the highest risk. These individuals deserve surveillance colonoscopy.