Prognostic variables
We utilized Cox proportional hazard modeling to determine factors that may have impacted survival in the study population (Table 4 ). On univariate analysis, three variables were identified that negatively affected EFS and OS in our cohort: anaplastic histology [compared to desmoplastic; OS: HR=3.5 (95% CI: 1.1 – 10.8), p=0.03; EFS: HR=3.4 (95% CI: 1.1 – 10.4), p=0.03], presence of metastasis at diagnosis [OS: HR=3.4 (95% CI: 1.3 – 9.1), p=0.01; EFS: HR=4.4 (95% CI: 1.6 – 11.7), p=0.003], and treatment post-2008 [OS: HR=2.5 (95% CI: 1.3 – 4.8), p=0.01; EFS: HR=2.5 (95% CI: 1.3 – 4.9); p=0.01]. Large residual tumors were not associated with decreased OS [HR=1.3 (95% CI: 0.6 – 3.1), p=0.52] or EFS [HR=1.4 (95% CI: 0.6 – 3.3); p=0.44]. No differences in survival were observed based on risk stratification [OS: HR=2.0 (95% CI: 0.8 – 4.1), p=0.13; EFS: HR=2.2 (95% CI: 0.9 – 5.5), p=0.09].