Global disease burden of viral hepatitis and hepatocellular carcinoma

The most common causes of hepatitis worldwide is a group of viruses known as hepatitis A, B, C, D and E virus. Most deaths from viral hepatitis are due to hepatitis B and hepatitis C. Globally, an estimated 257 million people were living with HBV and 71 million people were living with HCV, which caused 1.34 million deaths in 2015 comparable with deaths from tuberculosis and exceeding deaths from HIV.1

Both liver cancer, mostly hepatocellular carcinoma (HCC), and cirrhosis are end-stage clinical outcomes of chronic hepatitis B (CHB) and chronic hepatitis C (CHC).2 HBV and HCV are the main causes of liver cancer worldwide, and liver cancer was the seventh commonly diagnosed cancer and the second common cause of cancer death as reported in GLOBOCAN 2012.3 There was a significant increase in global deaths from liver cancer and cirrhosis from 1990 to 2013 with a 60% increase for liver cancer and a 45% increase for cirrhosis. Such increases are mostly attributable to the increase in infection of HBV and HCV.4

The incidence of liver cancer and the prevalence of HBV and HCV infection are high in the East, Southeast and Central Asia and the sub-Saharan Africa.1–4 However, the aetiological proportion of liver cancer varies in different countries and regions. HCV is more prevalent in patients with HCC in Japan, North America and Europe, and HBV is more prevalent in patients with HCC in Taiwan, Southeast Asia and China.1 2 Around 75% of global liver cancer cases are caused by chronic HBV and HCV infection,4 and control of viral hepatitis may thus significantly reduce the burden of HCC globally.

Natural history of chronic hepatitis B

The causality of chronic HBV infection to induce HCC was reported in several cross-sectional case-control studies2 and first confirmed by the GECC cohort study in Taiwan,5 …