Background: Clear cell sarcoma (CCS), epithelioid sarcoma, and synovial sarcoma are rare tumors historically identified as high risk for lymph node metastasis. Nodal metastasis in adults with these subtypes has been described. This study investigates incident nodal metastasis and associated survival in children with these subtypes. Procedure: Using the National Cancer Database (2004-2015), we created a retrospective cohort of 1303 patients (aged ≤25 years) who underwent local control therapy for CCS, epithelioid sarcoma, and synovial sarcoma. Kaplan-Meier curves estimated overall survival (OS) by subtype. Stratifying on subtype, Cox regressions assessed OS by lymph node sampling status and nodal metastasis. Results: There were 103 (7.9%) patients with CCS, 221 (17.0%) with epithelioid sarcoma, and 979 (75.1%) with synovial sarcoma. Lymph node sampling was more frequent in patients with CCS (56.3%) and epithelioid sarcoma (52.5%) versus synovial sarcoma (20.5%, p<0.001). Synovial sarcoma metastasized to lymph nodes less frequently than CCS or epithelioid sarcoma (2.2% vs. 14.6% and 15.0%, p<0.001). Across all subtypes, lymph node metastasis was associated with inferior OS (HR 2.10, CI 1.44-3.07, p<0.001). Lymph node sampling was associated with improved OS in CCS (HR 0.35, CI 0.15-0.78, p=0.010), inferior OS in synovial sarcoma (HR 1.60, CI 1.13- 2.25, p=0.007), and no statistical association with OS in epithelioid sarcoma. Conclusions: Lymph node metastasis is rare in children with synovial sarcoma. Lymph node sampling procedures were not consistently performed for patients with CCS or epithelioid sarcoma, but improved OS supports routine lymph node sampling in children with CCS.

Background: Socioeconomic and health care coverage disparities are established as poor prognostic markers in adults with sarcoma, but few studies examine these differences among pediatric, adolescent and young adults (AYA). This study examines the association between socioeconomic status (SES), insurance status, and disease presentation among children and AYA patients with sarcoma. Methods: This is a retrospective cohort study of patients aged 0-25 years with bone or soft tissue sarcoma from the National Cancer Database. SES assignments were based on estimated median income and education-level. Patient demographics and clinical factors were compared by SES and insurance status. Multivariate logistic regression models were fitted to determine adjusted odds ratios of SES and insurance status on metastatic disease or tumor size ≥5cm at time of presentation. Results: In a cohort of 9112 patients, 2932 (32.1%) had low, 2084 (22.8%) middle, and 4096 (44.9%) high SES. For insurance status, 5864 (64.3%) had private, 2737 (30.0%) public, and 511 (5.6%) were uninsured. Compared to high SES, patients with low SES were more likely to have metastatic disease (OR=1.16, p=0.03) and tumors ≥5cm (OR=1.29, p<0.01). Compared to private insurance, public and no insurance were associated with metastatic disease (OR=1.35, p<0.01 and OR=1.32, p=0.02) and increased tumors ≥5cm (OR=1.28, p<0.01 and OR=1.67, p<0.01). Conclusions: SES disparities exist among children and AYA patients with sarcoma. Low SES and public or no insurance are associated with advanced disease at presentation. Further studies are needed to identify interventions to improve earlier detection of sarcomas in at-risk children and young adults.