Comparative analysis of thyroid cancer burden between China and the U.S. from 2005 to 2019, and forecast for 2020–2035 based on the ARIMA model

Background The burden of thyroid cancer has increased in recent years, becoming a global public health issue. Its epidemiological trends vary by region and have not been fully studied. This study aimed to analyze its long-term incidence and mortality trends in China versus the U.S. Methods Using 2005–2019 data from the China Cancer Registry Annual Report (CCRAR) and SEER 21 databases, Joinpoint regression calculated annual percentage changes, age-period-cohort model analyzed cohort effects. Decomposition analysis quantified the contributions of population growth, aging, and epidemiological changes to variations in disease burden, and autoregressive integrated moving average (ARIMA) projected trends to 2035. Results China’s thyroid cancer incidence and mortality rose with average annual percent changes (AAPCs) of 10.41% and 2.02% respectively, while the U.S. maintained stable AAPCs (2.02% and 0.10%). Incidence coefficients increased with age then declined in older groups, but mortality coefficients rose steadily with age. China’s period effect intensified post-2014, whereas the U.S.’s weakened. The rising cancer burden resulted from changes in epidemiological trends. The ARIMA models showed that thyroid cancer incidence in China would keep rising but both countries would experience stable mortality rates. Conclusions The study demonstrated that thyroid cancer incidence in China experienced rapid growth because of radiation exposure and excessive cancer detection. The control of this trend requires implementation of better screening methods and enhanced surveillance systems, and also requires to prevent the increased burden of death caused by aging.