Department of Epidemiology, Fielding School of Public Health.
Department of Epidemiology, School of Public Health, Fudan University, Shanghai, People's Republic of China.
Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
Healthy and At-Risk Populations Program, Jonsson Comprehensive Cancer Center.
Center for Human Nutrition, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
To facilitate regionally specific liver cancer prevention and control, this study estimates the fraction of hepatocellular carcinoma (HCC) cases attributable to five major liver cancer risk factors by geographic region. Prevalence estimates of major HCC 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. Overall, 44% of HCC 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. In addition, strong sex disparities were observed when looking at lifestyle risk factors, particularly tobacco smoking, in Asia and Africa. Prominent risk factors for HCC vary depending on the region. Our findings provide useful data for developing regionally specific guidelines for liver cancer prevention and control worldwide.