The prevalence of sessile serrated lesion in the colorectum and its relationship to synchronous colorectal advanced neoplasia: a systemic review and meta-analysis

BACKGROUND: The aim of this systemic review and meta-analysis was to evaluate the prevalence of sessile serrated lesion (SSL) and its relationship to synchronous colorectal advanced neoplasia. MATERIALS AND METHODS: Comprehensive, computerized research was performed on PubMed and published from 1 January 2010 to 6 July 2018 which searched relevant articles without any language limitations. Clinical trials were included in the narrative systemic review if they matched the following inclusion criteria: (1) published as a case-controlled study, cohort study or cross-sectional study; (2) defined objectively for diagnosis of SSL within the studies; (3) addressed the prevalence and characteristics of SSL. Within these trials, if they met additional criteria involving the reported outcome of risk regarding advanced neoplasia in relation to SSL, they were enrolled into meta-analysis. RESULTS: Forty-one trials were enrolled for the systematic review, with a total of eight analyzed for the meta-analysis. The prevalence of all SSL ranged from 0.038 to 20.23% and the prevalence by pooled analysis was 2.7%. In a subgroup analysis, the overall prevalence of SSL during the periods of 2010–2014 and 2015–2018 was shown to be 2.7 and 2.8%, respectively. We calculated the pooled data on the cancer risk of SSL and the risk of synchronous advanced neoplasia in patients with SSL made available from the eight trials, which resulted in a pooled odds ratio of 3.53 (95% confidence interval 2.39–5.20, I(2) = 4%, P = 0.40). CONCLUSION: In this systemic review, SSL was found to be associated with an increased risk of synchronous advanced neoplasia in the colorectum.