Epidemiology of Thyroid Cancer in Kazakhstan and in Areas Adjacent to the Former Semipalatinsk Nuclear Test Site in 2013-2023

Abstract

This study aimed to investigate the incidence and mortality of thyroid cancer (TC) in the Republic of Kazakhstan and East Kazakhstan Region, which includes the areas adjacent to the former Semipalatinsk nuclear test site over the past ten years, from 2013 to 2023. Methods: The study included information from Form No. 7 Annual “Report on Patients with Malignant Neoplasms” and “Indicators of the Oncological Service of the Republic of Kazakhstan” for the period 2013-2023. Incidence and mortality rates were calculated per 100,000 population, and data were distributed by gender, age groups, clinical stages. The study included an analysis of trends in annual epidemiological indicators, which allows us to observe fluctuations in Incidence and mortality over time. Results: Overall, Republic of Kazakstan experienced a gradual increase in incidence, beginning at 2.9 per 100,000 population in 2013, peaking at 7.2 in 2019, and ending at 5.5 in 2023. East Kazakhstan, however, showed greater fluctuation, with rates ranging from 3.2 to 4.3 per 100,000, with a notable increase in 2023 to 4.7 per 100,000 population, the highest value observed in the study period. In East Kazakhstan, mortality remained steady at 0.4 per 100,000 from 2013 to 2016, briefly increasing to 0.9 in 2018, before stabilizing at 0.4 from 2020 to 2023. Nationwide, TC mortality varied between 0.3 and 0.5 per 100,000, with a gradual decline to 0.3 per 100,000 in 2021 and 2023. Conclusion: In the areas adjacent to the former Semipalatinsk nuclear test site, significant fluctuations and peaks in morbidity are observed, which differ from the general republican indicators.