Pediatric ependymoma: biological perspectives.
Pediatric ependymomas are enigmatic tumors that continue to present a clinical management challenge despite advances in neurosurgery, neuroimaging techniques, and radiation therapy. Difficulty in predicting tumor behavior from clinical and histological factors has shifted the focus to the molecular and cellular biology of ependymoma in order to identify new correlates of disease outcome and novel therapeutic targets. This article reviews our current understanding of pediatric ependymoma biology and includes a meta-analysis of all comparative genomic hybridization (CGH) studies done on primary ependymomas to date, examining more than 300 tumors. From this meta-analysis and a review of the literature, we show that ependymomas in children exhibit a different genomic profile to those in adults and reinforce the evidence that ependymomas from different locations within the central nervous system (CNS) are distinguishable at a genomic level. Potential biological markers of prognosis in pediatric ependymoma are assessed and the ependymoma cancer stem cell hypothesis is highlighted with respect to tumor resistance and recurrence. We also discuss the shifting paradigm for treatment modalities in ependymoma that target molecular alterations in tumor-initiating cell populations.
Kilday
John-Paul
JP
The Children's Brain Tumour Research Centre, University of Nottingham, United Kingdom.
Rahman
Ruman
R
Dyer
Sara
S
Ridley
Lee
L
Lowe
James
J
Coyle
Beth
B
Grundy
Richard
R
D000293:Adolescent; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D055028:Comparative Genomic Hybridization; D004806:Ependymoma / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D023281:Genomics; D006801:Humans; D007223:Infant
D014408:Biomarkers, Tumor