Discussion
The results of this study demonstrate that SES and insurance-related disparities in cancer burden exist among children and AYA patients diagnosed with sarcoma. After adjusting for confounders, our multivariate analysis revealed that SES and insurance status were independently associated with advanced disease at presentation. The presence of distant metastasis and larger tumors upon diagnosis are poor prognostic factors for adult and pediatric sarcoma patients.3,25 Therefore, the socioeconomic disparities in disease presentation found in our study have important implications for patient prognosis and our results highlight the need to improve access to medical care and early detection.
These findings are consistent with previous studies that have found that low SES, participation in public health insurance programs, and lack of insurance are associated with staging disparities and inferior survival across many pediatric cancers including thyroid cancer26, retinoblastoma27, leukemia28,29, and sarcoma.30However, these studies utilize different approaches in evaluation of SES and insurance status. In a study by Penumarthy et al., public insurance was found to be a risk factor for advanced disease at diagnosis and worse survival for pediatric and AYA patients with bone and soft tissue sarcomas in the University of San Francisco California Cancer Registry. In their study, public insurance was used as a proxy for low income as, under California state law, public insurance is only available to individuals with low-income.30 Given that public insurance eligibility varies by state, our findings add to the existing evidence by examining trends nationally and separating other markers of SES from insurance status.
Our results support the need for improved access to medical care and early detection in higher risk socioeconomic populations. Researchers have hypothesized that presentation with later stage disease is partially responsible for the association between SES and insurance-related survival disparities.31,32 In studies of adult cancer, low SES and poor insurance have been found to result in delays in diagnosis and time to treatment, which may account for the associated advanced disease and poorer outcomes.33,34 Our data suggest that a similar pattern may be occurring in the pediatric and AYA population. Successful sarcoma management may be challenging and requires a coordinated multidisciplinary approach at a center with expertise in the management of these rare cancers. Another possible mechanism for inferior survival may be related to limited access to cancer care centers, resulting in inferior treatment.
Limitations of our study include those inherent from a large centralized database, including its retrospective nature, missing data, and errors in coding. The NCDB does not provide individual level estimates of income and education level, and our measure of SES is an approximation based on zip codes of residence. In addition, other demographic variables not measured in this database may be surrogates for SES. In pediatric populations, SES and insurance status are dependent on a parent or guardian rather than the individual. This may present unmeasured confounders that we are unable to account for.