Thyroid Cancer Incidence Trends and Epidemiological Patterns in Saudi Arabia: A Retrospective Analysis of National Cancer Registry Data (2013–2022)

A BSTRACT Background: Thyroid cancer is the most rapidly increasing malignancy worldwide, with ionizing radiation recognized as its most established modifiable risk factor. Saudi Arabia has reported rising thyroid cancer incidence over recent decades, yet comprehensive national trend analyses remain limited. Objectives: The objective of the study is to characterize thyroid cancer incidence trends, epidemiological patterns, and demographic distribution in Saudi Arabia between 2013 and 2022 and to contextualize findings within global radiation risk and prevention frameworks. Materials and Methods: This retrospective cross-sectional study analyzed secondary data from the Saudi Cancer Registry (2013–2022), supplemented by GLOBOCAN 2022 estimates and published national health statistics. Annual age-standardized incidence rates (ASR) per 100,000 population were calculated using the World Standard Population. Data were analyzed by year, sex, age group, administrative region, histological subtype, and clinical stage at diagnosis. Descriptive statistics characterized incidence patterns; temporal trends were described narratively. Comparative analysis benchmarked Saudi rates against regional and global figures. Results: A total of 21,854 thyroid cancer cases were registered during the study period. Annual case counts increased from 1648 in 2013 to 2581 in 2022, representing a 56.6% absolute increase. Female predominance was consistent (female-to-male ratio 3.1:1). The ASR increased from 9.8 to 14.2/100,000 in women and from 2.9 to 4.1/100,000 in men. Papillary thyroid carcinoma accounted for 86.7% of cases. The Western region (Makkah) recorded the highest incidence (ASR 16.4/100,000). The 40–59 age group accounted for 51.3% of all cases. Localized disease at diagnosis comprised 68.4% of cases in 2022. A transient decline occurred during the coronavirus disease 2019 pandemic (2020), with a subsequent rebound. Conclusions: Thyroid cancer incidence in Saudi Arabia has risen substantially over the past decade, consistent with global trends and driven by a combination of improved detection, ultrasonographic surveillance expansion, and potential contributions from radiation exposure including medical diagnostic imaging. Targeted radiation protection strategies, risk-stratified screening protocols, and enhanced registry-based surveillance are essential preventive priorities.