Systematic Review with Meta-Analysis: Alcohol Consumption and Risk of Colorectal Serrated Polyp

Background: Alcohol intake is closely related to colorectal cancer, which remains inconsistent with studies on the relation between alcohol consumption and risk of colorectal serrated polyp (SP) which was proven to have potential of developing into malignant serrated neoplasm. Aim: A meta-analysis investigating the association between alcohol intake and colorectal SP with the dose–response of alcohol intake was conducted. Methods: The literature search was performed on PubMed to identify pertinent articles presenting results for at least three categories of alcohol consumption dated up to October 2014. Summarized relative risks (RRs) with 95 % confidence intervals (CIs) were estimated using random or fixed effects models based on statistical heterogeneity. Results: A total of ten observational studies were identified in this meta-analysis. All drinkers were associated with 24 % increased risk of colorectal SP compared with non-/occasional drinkers. In particular, the light alcohol intake was not related to an increased risk of colorectal SP (RR 1.05, 95 % CI 0.93–1.18), whereas the RRs were 1.19 (95 % CI 1.02–1.40) for moderate alcohol intake and 1.60 (95 % CI 1.35–1.91) for heavy alcohol intake. The risks were consistent in further dose–response analysis. Meanwhile, subgroup analyses demonstrated that patients in America had more increased risk of SP with respect to those in Europe and Asia. In terms of subtype of colorectal SP, alcohol consumption had a greater influence on SSA than HP. Conclusions: This is the first meta-analysis that demonstrated the relationship between moderate and heavy alcohol consumption and increasing risks of colorectal SP.