Histological and genetic features predict outcome in infratentorial ependymomas of childhood
Introduction: We aimed to identify outcome predictors in children with posterior fossa ependymomas.
Methods: Tumor samples of 132 patients aged 0.2 – 15.9 years treated according to HIT protocols were analyzed for histological features such as mitotic activity, necrosis and vascular proliferation and genomic alterations by SNP and molecular inversion profiling. Survival analysis was performed by Kaplan-Meier and Cox regression analysis.
Results: Residual tumor, chromosome 1q gain and structural genomic alterations were identified as predictors of significantly shorter event-free (EFS) and overall survival (OS). Vascular proliferation, necrosis and high mitotic activity were predictive for shorter OS. Multivariate Cox regression revealed residual tumor, chromosome 1q gain, vascular proliferation and high mitotic activity as independent predictors of OS; for EFS, chromosome 1q gain and residual tumor were predictive.
Conclusion: Assessment of residual tumor, chromosome 1q gain, mitotic activity and vascular proliferation allows risk-adapted stratification of children with infratentorial ependymomas.