Thyroid cancer trends in China and its comparative analysis with G20 countries: Projections for 2020-2040.

Background: Thyroid cancer, a leading type of endocrine cancer, accounts for 3-4% of all cancer diagnoses. This study aims to analyse and compare thyroid cancer patterns in China and the Group twenty (G20) countries, and predict these trend for the upcoming two decades. Methods: This observational longitudinal study utilised data from the Global Burden of Disease (GBD) study 2019. We used metrics including incidence, mortality, mortality-incidence ratio (MIR), age-standardised rate (ASR) and average annual percent change (AAPC) to examine thyroid cancer trends. Joinpoint regression analysis was used to identify periods manifesting notable changes. The association between sociodemographic index (SDI) and AAPC were investigated. The autoregressive integrated moving average (ARIMA) model was used to predict thyroid cancer trends from 2020 to 2040. Results: From 1990 to 2019, thyroid cancer incidence cases in China increased by 289.6%, with a higher AAPC of age-standardised incidence rate (ASIR) in men. Contrastingly, the G20 demonstrated a smaller increase, particularly among women over 50. Despite the overall age-standardised mortality rate (ASMR) was higher in the G20, the increase in mortality was less pronounced than in China. Age-standardised incidence rate increased across all age groups and genders, with a notable rise among men aged 15-49. ASMR decreased in specific age groups and genders, especially among women. Conversely, the ASMR significantly increased in group aged over 70. The MIR exhibited a declining trend, but this decrease was less noticeable in men and the group aged over 70. Joinpoint analysis pinpointed significant shifts in overall ASIR and ASMR, with the most pronounced increase in ASIR during 2003-2011 in China and 2003-2010 in the G20. Predictions suggested a continual ASIR uptrend, especially in the 50-69 age group, coupled with a predicted ASMR downturn among the elderly by 2040. Moreover, the proportion of thyroid cancer deaths attributable to high body mass index (BMI) escalated, with significant increase in Saudi Arabia and a rise to 7.4% in China in 2019. Conclusions: Thyroid cancer cases in incidence and mortality are escalating in both China and the G20. The increasing trend may be attributed to factors beyond overdiagnosis, including environmental and genetic factors. These findings emphasise the necessity for augmenting prevention, control, and treatment strategies. They also highlight the significance of international collaboration in addressing the global challenge posed by thyroid cancer.