Diverging Trajectories of Lung Cancer Burden in China, Japan, and South Korea: A Comparative Risk Assessment from the Global Burden of Disease Study 1990-2021.

OBJECTIVE: Lung cancer poses a major public health challenge in East Asia. This study aimed to compare the evolving burden of lung cancer and key risk factors from 1990 to 2021 in China, Japan, and South Korea, three neighboring countries with distinct socioeconomic and public health profiles. METHODS: Using data from Global Burden of Disease Study 2021, we applied an integrated analytical framework. This included Joinpoint regression to identify trend transitions, an Age-Period-Cohort model to disentangle demographic effects, and ARIMA time-series modeling for forecasting. Risk attribution and cluster analysis assessed contributions of behavioral, environmental, occupational, and metabolic factors. Marked disparities were observed. RESULTS: China's age-standardized mortality rate (ASMR) increased (Estimated Annual Percentage Change, EAPC = +0.25%), while Japan (EAPC = -0.91%) and South Korea (EAPC = -1.02%) experienced declines. Smoking remained the predominant risk factor (Attribution score: 10/10), but risk profiles diverged: ambient air pollution contributed 9/10 to China's burden, occupational asbestos dominated in Japan (Score: 8/10), and metabolic risks (high fasting plasma glucose) rose sharply in South Korea (+18.4% since 1990). The burden peaked in the 65-79 age group, with male mortality 3-8 times higher than females. Projections suggest stabilization in China (ASMR ~30.5 by 2050), continued decline in Japan (~12.0), and a potential rebound risk in South Korea by 2050. CONCLUSION: Lung cancer burden reflects divergent epidemiological transitions, shaped by socioeconomic development and public health policies. Precision prevention strategies are essential, prioritizing tobacco control and air quality in China, occupational risks in Japan, and metabolic factors in South Korea, supported by regional collaboration.