[Natural history of Japanese patients with non-alcoholic fatty liver disease (NAFLD), especially non-alcoholic steatohepatitis (NASH) patients with hepatocellular carcinoma (HCC)].

Our current knowledge of the natural history of NAFLD can be summarized as follows: 1) simple steatosis can progress to steatohepatitis, fibrosis, cirrhosis, and even liver-related death but progression occurs in less than 5% of patients, 2) patients with NASH can progress to cirrhosis, 3) once cirrhosis develops in patients with NAFLD the prognosis appears to be poor with several studies reporting that some patients develop HCC and up to a third of patients develop liver-related morbidity or mortality, 4) older age and advanced fibrosis are risk factors for HCC in NASH. Changes in lifestyle have resulted in a dramatic increase in the prevalence of NAFLD. It is extremely important that we diagnose NASH definitely and perform appropriate treatment.