Thyroid Cancer Burden in China: 1990 to 2021 Trends and 15-Year Projections Against Global Trends.

Objective: To analyze the temporal trends and turning points of thyroid cancer burden in China from 1990 to 2021 and project future incidence and mortality to 2035. Study Design: Cross-sectional study. Setting: Data were sourced from the Global Burden of Disease 2021 database. Methods: Temporal trends were evaluated using Joinpoint regression, and associations between cancer burden and sociodemographic indices were explored through frontier analysis. A Bayesian Age-Period-Cohort model was applied to project future disease burden through 2035. Results: In 2021, China reported 48,104 new thyroid cancer cases and 7692 deaths. From 1990 to 2021, the age-standardized incidence rate (ASIR) and prevalence rate (ASPR) increased markedly (average annual percentage change [AAPC]: 2.98% and 2.25%, respectively), whereas the age-standardized mortality rate (ASMR) and disability-adjusted life year rate (ASDR) declined (AAPC: -0.65% and -0.56%). A pivotal shift occurred around 2005: while ASMR and ASDR continued to decrease in both China and globally, China's ASIR and ASPR accelerated further, contrasting with a global deceleration. Projections indicate that China's ASIR for thyroid cancer is expected to increase more rapidly than the global average over the next 15 years. Conclusion: The thyroid cancer burden in China is characterized by rapidly rising incidence and stagnating mortality decline, a pattern distinct from global trends and likely driven by intensified detection. This escalating burden necessitates public health strategies focused on optimizing screening practices and managing overdiagnosis.