Associations of Socioeconomic Status, Public vs Private Insurance, and Race/Ethnicity With Metastatic Sarcoma at Diagnosis

This cross-sectional study evaluates whether socioeconomic status, insurance status, or race/ethnicity are associated with the presence of metastases at the time of diagnosis of sarcoma. Question Is the presence of metastases at diagnosis of sarcoma associated with socioeconomic status, race/ethnicity, or insurance status? Findings In this cross-sectional, population-based study of 47 & x202f;337 sarcoma cases, metastases at diagnosis of sarcoma was not associated with socioeconomic status as measured by small-area Census characteristics. Among adults, those with Medicaid insurance or no insurance had a higher odds of metastases at diagnosis of most soft-tissue sarcomas, but not bone sarcomas, whereas the racial disparities in the prevalence of metastatic leiomyosarcoma and unclassified sarcomas were not associated with small-area socioeconomic status and insurance status. Meaning These findings suggest that Medicaid insurance or no insurance is associated with the presence of metastases at the time of diagnosis among adults with soft-tissue sarcomas, suggesting a diagnostic delay, but there is no such association for adults with bone sarcomas. Importance Approximately 10% to 30% of patients with sarcoma present with detectable metastases at diagnosis. However, the extent to which presentation with metastases is due to delayed diagnosis vs other factors remains unclear. Objective To evaluate whether socioeconomic status, insurance status, or race/ethnicity were associated with the presence of metastases at diagnosis of sarcoma. Design, Setting, and Participants This cross-sectional study used data from the population-based Surveillance, Epidemiology, and End Results program. Adult and pediatric patients with an initial diagnosis of soft-tissue and bone sarcoma between 2001 and 2015 were stratified by age group (pediatric, <20 years; adult, 20-65 years; older adult, >65 years) and sarcoma subtype. Statistical analyses were performed between August 2019 and January 2020. Exposures Surveillance, Epidemiology, and End Results Census tract-level socioeconomic status index, insurance status, and race/ethnicity. Main Outcomes and Measures The odds of presenting with metastases at diagnosis were calculated. Results A total of 47 & x202f;337 patients with first primary malignant sarcoma were included (24 & x202f;343 male patients [51.4%]), with 29 & x202f;975 non-Hispanic White patients (63.3%), 5673 non-Hispanic Black patients (12.0%), 7504 Hispanic patients (15.8%), and 4185 American Indian-Alaskan Native and Asian Pacific Islander patients (8.8%). Liposarcoma in adults was the only subtype and age group combination that demonstrated a significant trend in incidence across socioeconomic status levels (odds ratio, 0.85; 99% CI, 0.76-0.96; P = .001). However, compared with having non-Medicaid insurance, having Medicaid or no insurance in adults was associated with an increased odds of metastases at diagnosis for 6 of the 8 sarcoma subtypes evaluated; osteosarcoma and Ewing sarcoma were the only 2 subtypes in adults for which metastases were not associated with insurance status. In addition, there was an increased risk of presenting with metastases among non-Hispanic Black adults diagnosed with leiomyosarcoma (odds ratio, 1.87; 99% CI, 1.41-2.48) and unclassified sarcomas (odds ratio, 1.65; 99% CI, 1.01-2.67) compared with non-Hispanic White adults that was independent of socioeconomic and insurance status. Conclusions and Relevance These findings suggest that delayed access to care is associated with advanced stage at diagnosis for several soft-tissue sarcoma subtypes in adults, whereas other factors may be associated with the metastatic progression of osteosarcoma and Ewing sarcoma, as well as the racial disparities observed with metastatic leiomyosarcoma and unclassified sarcomas.