Income disparities have a significant impact on thyroid cancer recurrence and survival.

[PURPOSE] Income inequality profoundly impacts cancer outcomes, yet its specific effects on thyroid cancer remain unclear. Elucidating the influence of socioeconomic disparities is imperative to advance health equity and optimize patient care. This study evaluates associations between median household income and thyroid cancer recurrence and survival using national cancer registry data.

[METHODS] 139,302 thyroid cancer patients undergoing surgery from 2000 to 2019 were analyzed from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were categorized by median annual household income at the county level (> or <$75,000). Multivariable regression determined the impact of income on recurrence and overall mortality.

[RESULTS] Higher-income patients had 26 % lower recurrence odds (OR 0.74, 95 %CI 0.55-0.99, p=0.042) and longer median survival (18.1 vs 17.7 years, p<0.001) compared to lower-income patients. On multivariate analysis, high income remained an independent predictor of reduced mortality after adjusting for demographics, tumor factors, and treatment (adjusted HR=0.84, 95 %CI=0.81-0.87, p<0.001). Cancer-directed surgery (HR=0.28, 95 %CI=0.26-0.30, p<0.001) and radioactive iodine (HR=0.69, 95 %CI=0.66-0.71, p<0.001) were associated with lower mortality risk.

[CONCLUSIONS] Income disparities have a significant influence on thyroid cancer outcomes, including lower recurrence and reduced mortality. Targeting socioeconomic inequity could substantially reduce recurrence, improve survival, and promote health equity for all patients.