Persistence of Disparity in Thyroid Cancer Survival After Adjustments for Socioeconomic Status and Access

Introduction Thyroid cancer incidence has increased substantially in the past 4 decades, estimated at 3.5% annually. Incidence is highest in white patients, yet black patients have the worst survival. Racial/ethnic differences in presentation and outcomes are hypothesized to be a result of differences in access to care. Analyses delineating the relative contribution of access to racial/ethnic survival disparities are scarce. We aimed to explore the association of delay in access to care and early/increased detection with racial/ethnic disparities in thyroid cancer survival. Methods The Surveillance, Epidemiology, and End Results (SEER) database was queried from 2007 to 2011 for patients with a first primary thyroid cancer diagnosis and up to 5 years of follow-up. Composite scores were generated from county-level variables to capture socioeconomic status and screening habits. Kaplan-Meier analysis and Cox proportional hazards models were utilized for survival analysis. Results We identified 46,970 patients (67% white, 7% black, 15% Hispanic, 10% Asian or Pacific Islander, and 1% unknown/other). Compared to white patients, black, Hispanic, and Asian or Pacific Islander patients were more likely to present with distant disease (3% vs 5%, 5%, and 6%, respectively; P < .001). After adjusting for sex, age, stage, subtype, tumor size, surgery, radiation, socioeconomics, and screening habits, black patients were the only race/ethnicity found to have increased odds of 5-year mortality compared to white patients (24%, P < .001). Conclusion Thyroid cancer survival is worst for black patients regardless of socioeconomic status or screening habits. Racial/ethnic disparities in survival are not attributable to early detection alone.

Automated summary

Thyroid cancer incidence has been increasing, with highest rates in white patients but worst survival in black patients. Racial/ethnic disparities in survival cannot be solely attributed to early detection, access to care is also an important factor.