Do geographic differences or socioeconomic disparities affect survival in sinonasal squamous cell carcinoma?

Background: Squamous cell carcinoma (SCC) is the most common malignancy in the sinonasal tract. We present the first population-based analysis that examines geographic differences in demographic and clinical characteristics, socioeconomic factors, treatment modality, and disease-specific survival (DSS) of this entity. Methods: All cases of sinonasal squamous cell carcinoma (SNSCC) were queried using the U.S. Surveillance, Epidemiology, and End Results (SEER) registry from 1973 to 2013. Patients were stratified by geographic location and characteristics such as demographics (age, gender, race, metropolitan/nonmetropolitan status, and income), stage at diagnosis, and treatment modality. Survival data were generated using Kaplan-Meier regression analysis. Results: In total, 6094 patients were identified; 15.3% were from the East, 16.3% from the Midwest, 19.3% from the South, and 49.1% from the West. Patients from the South were younger (p < 0.001). The South had the highest proportion of patients who were black (p < 0.001), lived in nonmetropolitan areas (p < 0.001), and presented with localized disease (p < 0.001). Southern patients also had the lowest median income (p < 0.05), and were least likely to be treated with both surgery and radiotherapy (p < 0.001). The South exhibited the lowest 20-year DSS compared to all other regions (p < 0.001). Conclusion: SNSCC patients from the South had the poorest long-term DSS, despite being most likely to present with localized disease. The South had the highest proportion of patients who were black, resided in rural or urban towns, had the lowest median income, and did not receive standard combination therapy, compared to the East, Midwest, and West.