Regional differences in thyroid cancer presentation and survival: A seer study

Objective: The incidence of thyroid cancer has been steadily increasing. Several studies have identified gender and racial/ethnic differences in the incidence and prognosis of thyroid cancer. In this study, we sought to determine if the stage of presentation and survival rate of patients with thyroid cancer in the United States is affected by geographic region.Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 100,404 patients diagnosed with thyroid cancer from 1973 through 2009. We assessed historical stage of diagnosis and cancer-free survival rate according to geographic region. To compare stages of diagnosis, we used multinomial logistic regression. To compare survival rates, we used Cox proportional hazards regression. Models were adjusted for age, year of diagnosis, cancer type, registry site, race/ethnicity, and stage.Results: Of 100,404 patients, 52,902 (52.7%) were from the West, 17,915 (17.8%) from the East, 15,302 (15.2%) from the South, and 14,285 (14.2%) from the Midwest. Overall, most patients presented with localized disease. Those from the West had a higher risk of presenting with regional and distant metastases. When we double-stratified by cancer subtype and racial group, we found no significant associations between geographic region and cancer-free survival rate.Conclusion: The presentation stage and survival rate of patients with thyroid cancer differs by geographic region, but not within separate racial/ethnic groups.