Abstract
BACKGROUND: Thymic epithelial tumors (TETs) are a group of rare thoracic malignancies with undefined global epidemiology. We aim to comprehensively characterize global patterns of TET incidence, explore their relationship with disease detection disparities, and thereby advance understanding and management of these malignancies. METHODS: Data were obtained from successive volumes of Cancer Incidence in Five Continents. Age standardized incidence rate (ASR) and average annual percentage change (AAPC) were calculated by age, sex, region, country, and Human Development Index (HDI) level. RESULTS: Globally, there were 25,473 cases of TETs among 1.27 billion people between 2013 and 2017, with an ASR of 0.26 per 100,000. From 1988 to 2017, the incidence of TETs has been gradually increasing worldwide (AAPC: 3.13). Most cases (70.2%) were diagnosed in people aged 50–79 years, and males had a higher incidence than females (Figure 1). There were significant ethnic differences in incidence, with Asian and Pacific Islanders having the highest ASR, followed by black people and then white people. There were large disparities in the incidence both between and within countries, which were found to be associated with HDI. In particular, the incidence of the same ethnicity was higher in high HDI countries than in low HDI countries. Most countries with high HDI had experienced a substantial increase in incidence, especially after 2003. However, the change in incidence was less pronounced in countries with relatively low HDI. CONCLUSIONS: This study provides a comprehensive global prevalence landscape of TETs, revealing marked variations in incidence across demographic, geographic, and temporal dimensions. In addition to inherent ethnic difference, these variations are closely associated with disparities in disease detection. This study highlights the need for greater attention to these rare malignancies and socio-economic inequities in healthcare.