NAFLD leads to liver cancer: do we have sufficient evidence?
Primary liver cancer has several well-recognized risk factors, such as HBV and HCV infection, alcohol abuse and aflatoxin. Recent studies show that nonalcoholic fatty liver disease (NAFLD), especially its aggressive form nonalcoholic steatohepatitis (NASH) is associated with an increased risk of liver cancer, mainly hepatocellular carcinoma (HCC). On the other hand, clinical and epidemiological data have showed that HCC has rarely been found in a "pure" fatty liver in human. Thus, the question we need to ask is do we have sufficient evidence to support a causative role of NAFLD in liver cancer? Furthermore, if NAFLD is indeed a causative factor for liver cancer, what is the mechanism? Perhaps at this stage, fatty liver and NASH can be regarded as a definite risk factor for liver cancer, but to conclude that NAFLD induces HCC requires more robust in vitro and in vivo data.
Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Children's Digestion and Nutrition, Shanghai 200092, China.
Xiao-Yan
XY
Duan
Department of General Surgery, The First Hospital of Lanzhou University, Lanzhou 730000, Gansu, China.
Lei
L
Zhang
Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Children's Digestion and Nutrition, Shanghai 200092, China. Electronic address: fanjiangao@gmail.com.
Jian-Gao
JG
Fan
Storr Liver Unit, University of Sydney at the Westmead Millennium Institute, Westmead, NSW 2145, Australia. Electronic address: liang.qiao@sydney.edu.au.
Liang
L
Qiao
D006528:Carcinoma, Hepatocellular / Q000209:etiology* / Q000276:immunology / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000276:immunology / Q000378:metabolism; D018450:Disease Progression; D005234:Fatty Liver / Q000150:complications* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008113:Liver Neoplasms / Q000209:etiology* / Q000276:immunology / Q000378:metabolism; D065626:Non-alcoholic Fatty Liver Disease; D011379:Prognosis; D012307:Risk Factors; D015398:Signal Transduction
D018836:Inflammation Mediators
Fatty liver; Hepatocellular carcinoma; Liver cancer; Nonalcoholic steatohepatitis