MON-421 - Race and Early Mortality in Anaplastic Thyroid Carcinoma: A Population-Based Analysis

Background
Anaplastic thyroid carcinoma (ATC) is a rare, highly aggressive malignancy with extremely poor survival, with a median overall survival of approximately 3–5 months and a 1-year survival rate of less than 20%. There have been studies on racial disparities in outcomes across this malignancy, but whether Black patients experience a higher early mortality rate following ATC diagnosis is unclear. We evaluated the association between race and early mortality along with overall survival in a large cohort.

Methods
We conducted a retrospective cohort study using data from the Surveillance, Epidemiology, and End Results (SEER) program. Patients diagnosed with ATC were included using ICD-10-CM code C73 with histology defined by ICD-O-3 morphology code 8021/3. Patients were then categorized as Black or non-Black. Early mortality was defined as death within 3 months of diagnosis. Descriptive statistics compared baseline characteristics by race. Early mortality was assessed using chi-square tests and logistic regression models, and overall survival was evaluated using Kaplan–Meier methods with log-rank testing and Cox proportional hazards regression. Multivariable models adjusted for age at diagnosis. Proportional hazards assumptions were assessed using Schoenfeld residuals.

Results
A total of 2,885 patients with ATC were included in this study. 246 (8.5%) were Black and 2,639 (91.5%) were non-Black. Early mortality occurred in 66.3% of Black patients and 64.0% of non-Black patients. Median survival was short in both groups. Kaplan–Meier analysis demonstrated no significant difference in overall survival by race. In unadjusted Cox regression, race was not associated with mortality. After adjustment for age, race remained non-significant, but increasing age was independently associated with higher mortality. Each additional year of age resulted in a 2.5% increase in the hazard of death (HR 1.03 per year, p< 0.001). Logistic regression analyses evaluating early mortality yielded consistent results, with
no significant association between race and early death before or after age adjustment. Proportional hazards assumptions were satisfied.

Conclusions
In this large, population-based analysis, Black patients with anaplastic thyroid carcinoma did not experience higher early mortality or worse overall survival compared with non-Black patients. Outcomes in ATC appear consistently poor across racial groups, confirming the aggressive nature of ATC and the need for evolving therapeutic strategies rather than any race-specific interventions.

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