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

Abstract

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 47 337 patients with first primary malignant sarcoma were included (24 343 male patients [51.4%]), with 29 975 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.

Figure 1.. Multivariable Adjusted Odds Ratios (ORs) and 99% CIs for Metastatic Sarcoma by Socioeconomic Status, Stratified by Age Group and Sarcoma Subtype: Surveillance, Epidemiology, and End Results 16 Registries, 2001-2015

All data are adjusted for race, sex, age at diagnosis, and year of diagnosis. ARMS indicates alveolar rhabdomyosarcoma; DSRCT, desmoplastic small round cell tumor; ES, Ewing sarcoma; F/MF, fibroblastic or myofibroblastic; GIST, gastrointestinal stromal tumor; MPNST, malignant peripheral nerve sheath tumor; RMS, rhabdomyosarcoma; and UPS, undifferentiated pleomorphic sarcoma.

Figure 2.. Multivariable Adjusted Odds Ratios (ORs) and 99% CIs for Metastatic Sarcoma in non-Hispanic Black vs non-Hispanic White Patients, Stratified by Age Group and Sarcoma Subtype: Surveillance, Epidemiology, and End Results 16 Registries, 2001-2015

All data are adjusted for small-area socioeconomic status (ordinal variable), sex, age at diagnosis, and year of diagnosis. ARMS indicates alveolar rhabdomyosarcoma; DSRCT, desmoplastic small round cell tumor; ES, Ewing sarcoma; F/MF, fibroblastic or myofibroblastic; GIST, gastrointestinal stromal tumor; MPNST, malignant peripheral nerve sheath tumor; RMS, rhabdomyosarcoma; and UPS, undifferentiated pleomorphic sarcoma.

Figure 3.. Multivariable Adjusted Odds Ratios (ORs) and 99% CIs for Metastatic Sarcoma in Hispanic vs non-Hispanic White Patients, Stratified by Age Group and Sarcoma Subtype: Surveillance, Epidemiology, and End Results 16 Registries, 2001-2015

ARMS indicates alveolar rhabdomyosarcoma; DSRCT, desmoplastic small round cell tumor; ES, Ewing sarcoma; F/MF, fibroblastic or myofibroblastic; GIST, gastrointestinal stromal tumor; MPNST, malignant peripheral nerve sheath tumor; RMS, rhabdomyosarcoma; and UPS, undifferentiated pleomorphic sarcoma.

Figure 4.. Multivariable Adjusted Odds Ratios (ORs) for Metastatic Sarcoma in American Indian and Alaska Native (AIAN) or Asian Pacific Islander (API) Patients vs non-Hispanic White Patients, Stratified by Age Group and Sarcoma Subtype: Surveillance, Epidemiology, and End Results 16 Registries, 2001-2015

ARMS indicates alveolar rhabdomyosarcoma; DSRCT, desmoplastic small round cell tumor; ES, Ewing sarcoma; F/MF, fibroblastic or myofibroblastic; GIST, gastrointestinal stromal tumor; MPNST, malignant peripheral nerve sheath tumor; RMS, rhabdomyosarcoma; and UPS, undifferentiated pleomorphic sarcoma.