Association between nonalcoholic fatty liver disease and extrahepatic cancers: a systematic review and meta-analysis
Abstract Background NAFLD was tightly associated with various diseases such as diabetes, cardiovascular disease, kidney disease and cancer. Previous studies had investigated the association between NAFLD and various extrahepatic cancers, but the conclusions were remains to be improved. The aim of this study was to investigate the association between NAFLD and various extrahepatic cancer comprehensively. Methods Electronic databases PubMed, EMBASE, Medline, and the Cochrane Library were searched for observational studies published from 1996 to January 2020. Observational studies that reflected the association between NAFLD and extrahepatic cancers were included in this study. The pooled OR/HR/IRR of the association between NAFLD and various extrahepatic cancers were analyzed. Results A total of 26 studies were included for investigating the association between NAFLD and various extrahepatic cancers. As the result shown, the pooled OR values of the risk of colorectal cancer and adenomas in patients with NAFLD were 1.72 (95%CI: 1.40-2.11) and 1.38 (95%CI: 1.22-1.56), respectively. The pooled OR values of the risk of intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma in patients with NAFLD were 2.40 (95%CI: 1.75-3.31) and 2.24 (95%CI: 1.58-3.17), respectively. The pooled OR value of the risk of breast cancer in patients with NAFLD was 1.68 (95%CI: 1.44-1.97). In addition, NAFLD was also tightly associatied with the risk of gastric cancer, pancreas cancer, prostate cancer, and esophagus cancer. Conclusions NAFLD could significantly increase the development risk of colorectal adenomas and cancer, intrahepatic and extrahepatic cholangiocarcinoma, breast cancer, gastric cancer, pancreas cancer, prostate cancer, and esophagus cancer.