Fish consumption and risk of esophageal cancer and its subtypes: a systematic review and meta-analysis of observational studies

Abstract

Inconsistent results regarding the association between fish intake and risk of subtypes of esophageal cancer (EC), esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), have been reported. To provide a quantitative assessment of this association, we summarized the evidence from observational studies. Relevant studies were identified in MEDLINE and EMBASE until 31 May, 2012. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were pooled with a random-effects model. Between-study heterogeneity was assessed using the Cochran's Q and I(2) statistics. A total of 24 studies (21 case-control and 3 cohort studies) were included in this systematic review and meta-analysis. The SRRs of ESCC were 0.81 (95% CI: 0.66-0.99) for those in the highest fish consumption category compared with those in the lowest consumption category, with significant heterogeneity among studies (P(heterogeneity)=0.007, I(2)=51.9%). Subgroup analysis suggested that a weak association between fish consumption and ESCC risk was shown in hospital-based case-control studies, but not in population-based case-control or cohort studies. According to high vs low analysis, fish consumption had no relationship with EAC risk (SRR=0.86, 95% CI: 0.61-1.22). Our results suggest that fish consumption is not appreciably related to risk of both ESCC and EAC.