Etiological changes of liver cirrhosis and hepatocellular carcinoma-complicated liver cirrhosis in Japan: Updated nationwide survey from 2018 to 2021

Aim: A nationwide survey in 2018 showed decreasing involvement of viral hepatitis and increasing involvement of nonviral liver diseases in the etiology of liver cirrhosis (LC) in Japan. An updated nationwide survey was undertaken in 2023. Methods: Cases of LC diagnosed between 2018 and 2021 were collected from 75 institutions, and the etiologies of LC were investigated. In addition, the data obtained were compared with the results of previous studies. Results: Among the 15 517 cases, alcohol-related liver disease (ALD)-associated LC was the most frequent cause (n = 5,487, 35.4%). Hepatitis C virus-associated LC, nonalcoholic steatohepatitis (NASH)-associated LC, and hepatitis B virus-associated LC were ranked as second, third, and fourth, respectively. In comparison to the previous survey, the ratios of viral hepatitis-associated LC decreased (HBV: from 11.5% to 8.1%; HCV: from 48.2% to 23.4%), while the ratios of ALD-associated LC and NASH-associated LC increased (from 19.9% to 35.4% and from 6.3% to 14.6%, respectively). Regarding cases of LC with hepatocellular carcinoma (n = 5906), HCV-associated LC (1986 cases, 33.6%) was the most frequent cause. Alcohol-related liver disease-associated LC, NASH-associated LC, and HBV-associated LC were the second-, third-, and fourth-ranked causes, respectively. In comparison to the previous survey, as the cause of hepatocellular carcinoma-complicated LC, HCV-associated LC decreased from 60.3% to 33.6%, while the ratios of ALD-associated LC and NASH-associated LC increased from 14.2% to 28.6% and from 4.2% to 14.0%, respectively. Conclusions: The major causes of LC in Japan are suggested to have been shifting from viral hepatitis to nonviral chronic liver diseases.