Epidemiologic trends and risk factor transitions in adolescent and young adult lung cancer in East Asia, 1990–2023.

e22587 Background: East Asia bears the highest global burden of adolescent and young adult (AYA) lung cancer. Updated regional assessments capturing recent epidemiologic trends and evolving risk-factor structures are limited. Methods: Using the Global Burden of Disease 2023, we report incidence rate (IR) and mortality rate (MR) per 100,000, and risk-factor–attributable mortality for AYA lung cancer (ages 15–49) from 1990–2023 in China, Japan, South Korea, North Korea, Taiwan, Mongolia, and globally, stratified by sex. Results: In 2023, IRs in all East Asia countries exceeded the global average (3.2). IR was highest in Taiwan (6.1), North Korea (5.9), and China (5.8), and lowest in Japan (3.2) and South Korea (3.4). IR was highest in Mongolia (7.3) in males and Taiwan (5.5) in females. From 1990–2023, IR declined globally (−24%) and in Japan (−29%) but increased in Taiwan (35%). In males, IR decreased globally (−30%), in Japan (−37%), and South Korea (−40%); but increased in Mongolia (88%) and Taiwan (6.8%). In females, IR increased in North Korea (94%) and Taiwan (53%). In 2023, MRs exceeded the global average (2.45 per 100,000) in North Korea (4.8), China (4.4), Taiwan (4.4), and Mongolia (4.1), but remained lower in Japan (1.8) and South Korea (2.0). MR was highest in Mongolia (6.1) for males and North Korea (3.9) for females. From 1990–2023, MR declined globally (−27%), in Japan (−44), and South Korea (−46%) but increased in Taiwan (22%). In males, MR decreased globally (−32%), in Japan (−49%), and South Korea (−55%) but increased in Mongolia (87%). In females, MR decreased in Japan (−33%) but increased in North Korea (87%) and Taiwan (34%). In 2023, 78–84% of male and 44–62% of female deaths were attributable to modifiable risks. Tobacco accounted for 63–74% of male deaths and 23–43% of female deaths. Smoking increased in China and Mongolia in males and decreased in Japan and South Korea. Secondhand smoke decreased in Japan, South Korea, and Taiwan in females. Air pollution accounted for 7.7–39% of deaths with mortality mainly from ambient particulate matter except in North Korea, where household solid fuels accounted for 31–35% of deaths. Overall air pollution declined or stabilized, but ambient particulate matter increased markedly in China (137–220%) and Mongolia (267–263%). Occupational carcinogens accounted for 4.7–12% of deaths and increased from 1990–2023 in all countries except Japan and South Korea. High fasting plasma glucose related deaths increased in Mongolia and Taiwan. Conclusions: AYA lung cancer trends in East Asia vary widely by country and sex. Only Japan and South Korea had declines in mortality rates, coinciding with reduced male tobacco-attributable mortality, while other countries had stagnant or increasing burden. Urgent policy measures must strengthen tobacco control and address environmental, occupational, and metabolic risks to reduce preventable deaths.