Proportion of liver cancer cases and deaths attributable to potentially modifiable risk factors in China

Understanding the differences in the burden of liver cancer due to different risk factors across provinces is critical to informing and improving liver cancer prevention and control. In this study, we estimated the population attributable fractions (PAFs) of liver cancer in all 31 provinces of China in 2016.Prevalence estimates of risk factors were derived from representative surveys. We used pooled relative risks obtained from several recent large-scale pooled analyses or high-quality meta-analyses. We calculated PAFs using multiple formulas which included exposure prevalence and relative risk data stratified by sex, age and province, and then combined and created overall PAFs by sex, risk factors and risk factor groups.Approximately 252 046 liver cancer cases {69.5% [95% confidence interval (CI) 52.6, 76.5]} and 212 704 deaths [67.7% (95% CI 50.9, 74.6)] were attributable to modifiable risk factors in China in 2016. The overall PAF for liver cancer was approximately 1.5 times higher in men than in women, with the top three risk factors in men being hepatitis B virus (HBV), smoking and alcohol drinking, whereas in women, they were HBV, excess body weight and hepatitis C virus (HCV). Among the risk factor groups, infectious agents had the highest PAF, followed by behavioural factors and metabolic factors.The PAF for liver cancer caused by modifiable risk factors varies widely among provinces and socioeconomic and geographical regions in China. The use of tailored primary prevention strategies across provinces and socioeconomic and geographical regions has great potential to reduce the burden and disparities of liver cancer.