The association between metabolic syndrome and primary liver cancer: A meta-analysis.

Abstract

175 Background: The Metabolic syndrome (MetS) and/or its individual components have been liked to the development of cancer. Recent studies have suggested a similar link to Primary Liver Cancer (PLC). The mechanism for the development of cancer in this group of patients remains unclear. The aim of this study was to evaluate the direction and magnitude of the association between the MetS and PLC. Methods: Two reviewers independently conducted a systemic search of the PubMed, OvidSP and Cochrane Library databases from January 1980 to July 2011. Search terms included ‘Metabolic syndrome’, ‘insulin resistance syndrome’ combined with ‘hepatocellular carcinoma’, ‘liver cancer’ and ‘GI malignancy’. No language restriction was applied to the search. Only studies reporting an effect measure for the association between MetS and PLC were eligible for inclusion. Metabolic syndrome was defined according to NCEP/ATP III, IDF, AHA and WHO guidelines. Identified articles were reviewed for additional references. Combined analysis including all studies was done using a random effects model. Publication bias was assessed using the Begg and Egger’s tests, with a visual inspection of funnel plot. All analyses were performed using Comprehensive Meta-Analysis version 2 software. Results: Five studies (4 cohort and 1 case-control) including 863,714 participants were included in the analysis. The age range of participants was between 20 and 88 years. The combined analysis showed an overall 74% increase risk of PLC in cases with MetS (RR: 1.74, 95% CI: 1.36-2.24). After excluding the single case-control study from analysis, the overall risk ratio remained statistically significant (RR: 1.62, 95% CI: 1.22-2.15). Funnel plot inspection, Begg and Egger’s tests showed no evidence of publication bias, whether in the combined or subgroup analysis. Conclusions: Though studies are scarce, currently available epidemiologic data is suggestive of positive association with significantly higher risk of liver cancer among patients with metabolic syndrome. More studies are required before reaching conclusive statement regarding this association. Further better-designed studies with good quality data with definitely aid in strengthening this association.