Metabolic syndrome relates to high risk in hepatocellular carcinoma: a meta-analysis

Metabolic syndrome (MetS) has been linked to the development of cancer. The relationship between MetS and hepatocellular carcinoma (HCC) remains controversial. Studies up to September 2017 of MetS and HCC were systematically identified and meta-analyzed. Ten studies (nine cohorts and one case-control) were included in this meta-analysis. It was found that MetS patients are significantly more likely to develop HCC (RR = 1.60, 95%CI = 1.12-2.28, P = 0.01). Additionally, when only cohort studies were included, MetS is a potential risk factor for HCC occurrence (RR = 1.52, 95%CI = 1.01-2.30, P = 0.05). Interestingly, subgroup analysis showed that male patients with MetS are more likely to develop HCC compared with female patients (RR = 1.91, 95%CI = 1.38-2.65, P < 0.0001 in male and RR = 2.1, 95%CI = 0.69-6.37, P = 0.19 in female). Additionally, MetS could significantly increase the risk of HCC in the Euro-US population (RR = 1.71, 95%CI = 1.09-2.67, P = 0.02). In conclusion, metabolic syndrome might be associated with a high risk of HCC occurrence, especially in male and the Euro-US population. However, no statistical significances were found between MetS and HCC clinicopathological features including capsule, vascular invasion, and moderate-poor differentiation, and between MetS and HCC survivals. Prospectively, well-designed trials with large numbers of samples should be conducted to evaluate the links between MetS and HCC.