Abstract 4924: Geographic and racial/ethnic differences in stage at diagnosis and survival among adolescents and young adults with thyroid cancer in the United States: An analysis of 2000-2021 SEER data

Abstract Objectives: Relatively few studies have focused on thyroid cancer in the adolescent and young adult (AYA) population. The objective of this study was to examine racial and geographic predictors of thyroid cancer outcomes in the AYA population. Methods: This population-based longitudinal study uses data from the Surveillance, Epidemiology, and End Results (SEER)-22 registries database. All primary cases of malignant thyroid cancer (including papillary, follicular, medullary, and anaplastic thyroid cancers) from 2000 to 2021 diagnosed among individuals aged 15-39 were included. Multinomial logistic regression models were used to compute the association between race/ethnicity and rurality (measured using Rural Urban Continuum codes) with stage at diagnosis (measured using SEER summary stages: localized, regional, or distant). Cox proportional hazards regression models were used to compute the association between race/ethnicity and rurality and both cancer-specific and all-cause mortality. Directed acyclic graphs were used to identify variables to adjust for in the multivariable analyses to control for confounding. Results: Our study included 74, 215 AYAs with thyroid cancer (93.04% papillary, 5.89% follicular, 1.03% medullary, and 0.04% anaplastic). Approximately 8% of the cases were diagnosed in rural counties. Compared to those diagnosed in rural counties, those in urban counties were more likely to be diagnosed with regional vs. localized cancer (aOR=1.17, 95% CI: 1.10-1.25). Compared to Non-Hispanic White AYAs, Hispanic AYAs are more like to be diagnosed with regional (aOR=1.48, 95% CI: 1.41-1.52) and distant (aOR=2.00, 95% CI: 1.74-2.30) cancer vs localized cancer. Among AYAs with thyroid cancer, living in a rural county at diagnosis was associated with an increased risk of all-cause mortality (aHR=1.41, 95% CI: 1.13-1.76). Additionally, compared to non-Hispanic White AYAs, the risk of thyroid cancer-specific mortality was highest among non-Hispanic Black (aHR=3.66, 95% CI: 2.37-5.65) and Hispanic (aHR=1.85, 95% CI: 1.32-2.60) AYAs. Conclusion: We observed racial and geographic differences in thyroid cancer stage at diagnosis and survival among AYAs in the United States. Future research should explore the underlying causes of these disparities and identify potential opportunities for intervention. Citation Format: Emma Hymel, Krishtee Napit, Josiane Kabayundo, Amelia Nichols, Shinobu Watanabe-Galloway. Geographic and racial/ethnic differences in stage at diagnosis and survival among adolescents and young adults with thyroid cancer in the United States: An analysis of 2000-2021 SEER data [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4924.