Transition in the etiology of liver cirrhosis in Japan: a nationwide survey

Background: To assess the recent real-world changes in the etiologies of liver cirrhosis (LC) in Japan, we conducted a nationwide survey in the annual meeting of the Japan Society of Hepatology (JSH). Methods: We investigated the etiologies of LC patients accumulated from 68 participants in 79 institutions (N = 48,621). We next assessed changing trends in the etiologies of LC by analyzing cases in which the year of diagnosis was available (N = 45,834). We further evaluated the transition in the real number of newly identified LC patients by assessing data from 36 hospitals with complete datasets for 2008–2016 (N = 18,358). Results: In the overall data, HCV infection (48.2%) was the leading cause of LC in Japan, and HBV infection (11.5%) was the third-most common cause. Regarding the transition in the etiologies of LC, the contribution of viral hepatitis-related LC dropped from 73.4 to 49.7%. Among the non-viral etiologies, alcoholic-related disease (ALD) and nonalcoholic steatohepatitis (NASH)-related LC showed a notable increase (from 13.7 to 24.9% and from 2.0 to 9.1%, respectively). Regarding the real numbers of newly diagnosed patients from 2008 to 2016, the numbers of patients with viral hepatitis-related LC decreased, while the numbers of patients with non-viral LC increased. Conclusions: HCV has remained the main cause of LC in Japan; however, the contribution of viral hepatitis as an etiology of LC is suggested to have been decreasing. In addition, non-viral LC, such as ALD-related LC and NASH-related LC, is suggested to have increased as etiologies of LC in Japan.