The Way to Decoding Pathogenesis and Conquering of National Afflictions, Viral Hepatitis and Liver Cancer

Viral hepatitis and liver cancer are worldwide health problems, and they have been called national afflictions in Japan. We have been studying the mechanism of hepatocarcinogenesis, chiefly using experimental animal models, starting from clinical observations of patients. Observations of the early development of liver cancer in young patients with chronic hepatitis B with minimal hepatic inflammation and fibrosis, as well as the frequent development of hepatic steatosis in patients with chronic hepatitis C, prompted us to study direct roles of hepatitis viruses B and C in such liver pathogenesis. In addition, our establishment of a new paradigm, “hepatitis C as a metabolic disease,” further led us to elucidating the mechanism of nonviral, metabolism-associated liver cancer. Most hepatologists may appreciate a conquest in the war against viral hepatitis and associated liver cancer. However, even if we conquer the external enemies, hepatitis viruses B and C, an intrinsic enemy, metabolism-associated liver disease, would be waiting for us as an alternative cause of liver cancer. Confrontation of liver cancer has never ended.