Hepatitis B virus and host factors
Primary liver cancer is the third most common cause of cancer-related deaths worldwide, with a particularly high incidence in Asian countries. Hepatocellular carcinoma (HCC) accounts for 85-90% of primary liver cancers, and is responsible for approximately 660,000 deaths worldwide each year (1). Hepatitis B virus (HBV) is the most common cause of infectious liver diseases. About 400 million people suffer from chronic HBV infection worldwide, and approximately 60% of HCC cases each year are related to chronic HBV infection (2). It has been suggested that viral factors (e.g., HBV-DNA levels, genotypes, and genomic mutations), host factors (e.g., age, sex, race, and immune status), and unhealthy lifestyles might contribute to the progression of liver diseases (3).