Trends in Cancer Incidence and Potential Associated Factors in China.

Importance: Timely analysis of cancer incidence trends is crucial for cancer prevention and control, which is a public health priority in China. Objective: To estimate incidence trends for 32 cancers in China from 1983 to 2017 and project changes to 2032, assessing distinct changes due to risk factors and an aging population. Design, Setting, and Participants: This population-based cohort study used data from the Cancer Incidence in Five Continents database (1983-2017). New cases of 32 cancers were collected. Data were analyzed from October 15, 2023, to May 23, 2024. Main Outcomes and Measures: Age-standardized incidence rate (AIR) standardized to the World Health Organization World Standard Population, average annual percentage changes (AAPC) using joinpoint regression, and percentage change due to aging and risk factors, using Møller decomposition analysis, stratified by cancer and sex. Results: A total of 3 677 027 new cancer cases (54.9% male, 45.1% female) were included in the analysis. Increased AIRS were observed for 11 cancers in males and 14 in females from 1983 to 2017, with trends expected to continue until 2032. Thyroid cancer showed the highest increase (AAPC: 7.82% in males; 95% CI, 6.92%-10.38%; 8.59% in females; 95% CI, 7.84%-10.42%), followed by prostate (4.71%; 95% CI, 3.12%-9.95%) and kidney (3.61%; 95% CI, 3.11%-5.82%) cancers in males, and cervical (4.43%; 95% CI, 3.36%-9.44%) and kidney (3.66%; 95% CI, 2.98%-6.86%) cancers in females. The AIRs of lung cancer tended to decrease in males but increase in females during 1983-2017. In contrast, the AIRs of stomach, liver, larynx, and nose and sinuses cancers decreased from 1983 to 2032. From 2018 to 2032, cancer cases were projected to increase primarily due to risk factors for 18 cancers in males and 11 in females, while aging would be associated with the increase in other cancers. Conclusions and Relevance: In this population-based cohort study of incident cancer in the general population, the cancer landscape in China is evolving, with an increasing incidence primarily due to risk factors in 20 cancers and aging in others. Primary prevention efforts to reduce risk exposure are crucial, and further basic research is needed. Additionally, second prevention efforts are imperative to improve cancer survival, particularly among older individuals.