County Rurality is Associated with Increased Tumor Size and Decreased Survival in Patients with Ewing Sarcoma.

Background: Ewing Sarcoma (ES) is an aggressive tumor affecting adolescents and young adults. Prior studies investigated the association between rurality and outcomes, although there is a paucity of literature focusing on ES. Objective: This study aims to determine whether ES patients in rural areas are subject to adverse outcomes. Methods: This study utilized the Surveillance, Epidemiology, and End Results (SEER) database. A Poisson regression model was used with controls for race, sex, median county income, and age to determine the association between rurality and tumor size. A multivariate Cox Proportional Hazard Model was utilized, controlling for age, race, gender, income, and tumor size. Results: There were 868 patients eligible for analysis, with a mean age of 14.14 years. Of these patients, 97 lived in rural counties (11.18%). Metropolitan areas had a 9.50% smaller tumor size (p<0.0001), compared to non-metropolitan counties. Patients of Black race had a 14.32% larger tumor size (p<0.0001), and male sex was associated with a 15.34% larger tumor size (p<0.0001). The Cox Proportional Hazard model estimated that metropolitan areas had a 36% lower risk of death over time, compared to non-metropolitan areas (HR: 0.64, p ≤ 0.04). Conclusion: Patients in metropolitan areas had a smaller tumor size at time of diagnosis and had a more favorable survival rate for cancer-specific mortality compared to patients residing in rural areas. Further work is needed to examine interventions to reduce this discrepancy and investigate the effect of extremely rural and urban settings and why racial disparities occur.