Gene Expression Profiling of Ewing Sarcoma Tumors Reveals the Prognostic Importance of Tumor-Stromal Interactions [COG]

For the current study we performed whole genome expression profiling on two independent cohorts of clinically annotated, localized Ewing sarcoma (ES) tumors in an effort to identify and validate prognostic gene signatures. ES specimens were obtained from the Children’s Oncology Group (COG) and whole genome expression profiling performed using Affymetrix Human Exon 1.0 ST arrays. Lists of differentially expressed genes between survivors and non-survivors were used to identify prognostic gene signatures 46 samples obtained from the COG Biorepository in Columbus, Ohio (Cooperative Human Tissue Network - CHTN) were prospectively acquired from patients on clinical trials INT-0154 (CCG-7942, POG-9354) and AEWS0031, the two most recent COG clinical protocols for patients with localized Ewing sarcoma (ES). An independent set of 39 tumors samples was obtained from the EuroEwing tumor biorepository in Muenster, Germany and were prospectively acquired from patients registered on EICESS 92 (European Intergroup Cooperative Ewing's Sarcoma Study) and EuroEwing 99. Gene expression was compared between between survivors and non-survivors, and differentially expressed genes used to identify prognostic gene signatures