Impact of changing the prevalence of smoking, alcohol consumption and overweight/obesity on cancer incidence in China from 2021 to 2050: a simulation modelling study

BACKGROUND: Smoking, alcohol consumption and overweight/obesity are key cancer risk factors contributing to the cancer burden in China. We aimed to quantify the cancer burden in China associated with smoking, alcohol consumption and overweight/obesity, and estimate the potential effect for cancer prevention interventions under different scenarios. METHODS: We used a macro-simulation approach called Prevent Model to estimate for a 30-year study period (2021–2050) numbers and proportions of future avoidable cancer cases under different scenarios of reducing the prevalence of smoking, alcohol consumption and overweight/obesity in Chinese adults. Cancer incidence was predicted under three scenarios: elimination, ambitious target (between elimination and manageable target) and manageable target (from national policy or global action plan). Risk factor prevalence was obtained from China Chronic Disease and Risk Factor Surveillance, and cancer incidence data were derived from the China Cancer Registry Annual Report. Relative risks were obtained from several recent large-scale studies or high-quality meta-analysis. Population data were extracted from the China Population & Employment Statistical Yearbook, China Health Statistical Yearbook and World Population Prospects. FINDINGS: Estimates of the avoidable cancer burden varied with different scenarios. In the theoretical maximum intervention scenario, where the prevalence of smoking, alcohol consumption and overweight/obesity would be eliminated, 9.17% (males: 13.50%; females: 1.47%) of smoking-related cancer cases, 7.06% (males: 11.49%; females: 1.00%) of cancer cases related to alcohol consumption and 8.22% (males: 7.91%; females: 8.52%) of overweight/obesity-related cancer cases were estimated to be avoidable during 2021–2050. Other scenarios, with more moderate goals in the exposure prevalence of smoking, alcohol use and overweight/obesity were also found to be associated with substantial reductions in the future cancer burden. INTERPRETATION: Our results suggested that a substantial number of future cancer cases could be avoided in Chinese adults by reducing the prevalence of smoking, alcohol consumption and overweight/obesity. FUNDING: National Science & Technology Fundamental Resources Investigation Program of China; Sanming Project of Medicine in Shenzhen.