Racial and Ethnic Differences in Sarcoma Incidence Are Independent of Census-Tract Socioeconomic Status

Epidemiologic analyses of sarcoma are limited by the heterogeneity and rarity of the disease. Utilizing population-based surveillance data enabled us to evaluate the contribution of census tract-level socioeconomic status (CT-SES) and race/ethnicity on sarcoma incidence rates. We utilized the Surveillance, Epidemiology, and End Results program to evaluate associations between CT-SES and race/ethnicity on the incidence rates of sarcoma. Incidence rate ratios and 99% confidence intervals were estimated from quasi-Poisson models. All models were stratified by broad age groups (pediatric: 200 total cases. A value less than 0.01 was considered statistically significant. We included 55,415 sarcoma cases in 35 sarcoma subtype-age group combinations. Increasing CT-SES was statistically significantly associated with 11 subtype-age group combinations, primarily in the older age group strata (8 subtypes), whereas malignant peripheral nerve sheath tumors in adults were associated with decreasing CT-SES. Nearly every sarcoma subtype-age group combination displayed racial/ethnic disparities in incidence that were independent of CT-SES. We found race/ethnicity to be more frequently associated with sarcoma incidence than CT-SES. Our findings suggest that genetic variation associated with ancestry may play a stronger role than area-level SES-related factors in the etiology of sarcoma. These findings provide direction for future etiologic studies of sarcomas.