LAUSR

6564 Background: Improvements in pediatric cancer survival are attributed to cooperative clinical trials. Under representation of specific demographic groups has been described in adult and pediatric cancer and poses a threat to the generalizability of trial results. A comprehensive evaluation of data provided by the Children’s Oncology Group (COG) of upfront trial enrollment for US patients 0 to 29 years old between 2004 and 2015 was performed to assess for disparities in participation. Methods: Estimates of cancer cases were calculated using the Surveillance, Epidemiology, and End Results registry and the US Census and compared to observed COG cases. Percent enrollment and Standardized Ratios of enrollment were calculated across various demographic, disease, and socioeconomic groups. The COG website was utilized to quantify available upfront trials during the study period and assess age eligibility criteria. Results: 21.3% of estimated US cancer patients age 0 to 19 years enrolled on COG trials. Younger patients were consistently more represented across disease types and race/ethnicities. Patients with hematologic malignancies were more represented compared to solid and central nervous system (CNS) tumors. Conclusions: COG clinical trial enrollment rates are declining, which may be due to challenges in pediatric drug development, difficulty designing feasible trials for highly curable diseases, and issues in ensuring trial availability for the heterogeneous group of solid and CNS tumors. Though racial/ethnic groups and county-level socioeconomic factors were proportionally represented, under representation of the adolescent/young adult (AYA) population and younger patients with solid and CNS tumors remain significant concerns. Targeted enrollment efforts should focus on the identified subgroups and further research should evaluate AYA enrollment across all available trials to provide continued treatment advances for all patients.