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.