Worldwide incidence of hepatocellular carcinoma cases attributable to major risk factors

OBJECTIVE: In order to facilitate regionally-specific liver cancer prevention and control, this study estimates the fraction of hepatocellular carcinoma cases attributable to five major liver cancer risk factors by geographic region. METHODS: Prevalence estimates of major hepatocellular carcinoma risk factors, including chronic infection with hepatitis B and hepatitis C, alcohol drinking, tobacco smoking, obesity, and diabetes were extracted for each country from the literature, along with recent incidence and risk estimate data, to calculate regionally specific population attributable fractions. RESULTS: Overall, 44% of hepatocellular carcinoma cases worldwide were attributable to chronic hepatitis B infection, with the majority of cases occurring in Asia. Hepatitis C was responsible for 21% of cases. Lifestyle risk factors such as alcohol drinking and obesity were responsible for a larger percentage of cases in North America and Western, Central, and Eastern Europe. Additionally, strong gender disparities were observed when looking at lifestyle risk factors, particularly tobacco smoking, in Asia and Africa. CONCLUSIONS: Prominent risk factors for hepatocellular carcinoma vary depending on region. Our findings provide useful data for developing regionally specific guidelines for liver cancer prevention and control worldwide.