Etiology of liver cirrhosis in Japan: a nationwide survey

Little is understood about worldwide changes in the epidemiological distribution of the etiology of liver cirrhosis (LC). The present study examines the etiology of liver cirrhosis in Japan using a nationwide survey. We analyzed data from 33,379 patients with LC at 58 hospitals and presented the findings in a poster symposium regarding the etiology and clinical features of LC in Japan that was included in the program of the 44th Annual Meeting of the Japan Society of Hepatology. We identified the distribution of the etiology of LC and compared the present with previous Japanese findings to estimate the future of etiological changes in LC. The etiological agents were as follows: hepatitis B virus (HBV) 13.9%, hepatitis C virus (HCV) 60.9%, alcohol 13.6%, primary biliary cirrhosis (PBC) 2.4% and autoimmune hepatitis (AIH) 1.9%. Cirrhosis was considered to be related to nonalcoholic steatohepatitis (NASH) in 2.1% of the patients. The ratio of HCV-related LC was significantly higher among patients with hepatocellular carcinoma (HCC) (P < 0.0001) compared to those without, whereas the ratios of alcohol, PBC, AIH were lower. HCC was evident in 31.5% of NASH-related LC. The major etiology of liver cirrhosis in Japan remains HCV. Our survey revealed the prevalence of NASH-related LC in Japan and the frequency of HCC. Future changes in etiology must be considered in establishing preventive or educational strategies, as well as in developing new treatment strategies.