The role of resection alone in select children with intracranial ependymoma: the Canadian Pediatric Brain Tumour Consortium experience.
OBJECTIVE
Gross total resection (GTR) of intracranial ependymoma is an accepted goal. More controversial is radiotherapy deferral. This study reports on children treated with gross total resection who did not receive upfront adjuvant radiotherapy.


METHODS
We conducted a retrospective review of children with intracranial ependymoma in 12 Canadian centers. Patients who had GTR of their tumor and no upfront radiotherapy were identified. Immunostaining was performed for Ki-67, epidermal growth factor receptor (EGFR), and EZH2 on archived tissue. The Kaplan-Meier survival analysis was performed and compared with those who had GTR followed by radiation.


RESULTS
Twenty-six children were identified treated with GTR alone at diagnosis; 12 posterior fossa ependymoma (PFE) WHO grade II, and 14 supratentorial ependymoma (STE). Progression-free survival (PFS) in ependymoma treated with GTR alone at diagnosis was inferior in those with high Ki-67 or positive EZH2 immunostaining. Survival was inferior for patients less than 2 years old at diagnosis (p = 0.002). Survival was comparable to PFE WHO grade II and STE who had GTR followed by radiation (p = 0.62). Five-year PFS and overall survival (OS) of those treated with GTR alone were 60 and 70% respectively for PFE and 45 and 70% respectively for STE (p = 0.2; 0.55).


CONCLUSIONS
This study suggests that there is a subset of children with certain biologic features who, in the setting of a prospective clinical trial, might be candidates for observation following GTR. Good risk factors for this approach include age of 2 years or older, low Ki-67, and negative EZH2. If relapse occurs, it may be confined to the primary site, allowing for possible salvage with GTR followed by XRT.
Division of Neurology and Oncology, Department of Pediatrics, British Columbia Children's Hospital, Room K3-147, 4480 Oak Street, Vancouver, BC, V6H3 V4, Canada.
Tamir
T
Ailon
Christopher
C
Dunham
Anne-Sophie
AS
Carret
Uri
U
Tabori
P Daniel
PD
Mcneely
Shayna
S
Zelcer
Beverley
B
Wilson
Lucie
L
Lafay-Cousin
Donna
D
Johnston
David D
DD
Eisenstat
Marianna
M
Silva
Nada
N
Jabado
Karen Jane
KJ
Goddard
Chris
C
Fryer
Glenda
G
Hendson
Cynthia
C
Hawkins
Sandra
S
Dunn
Stephen
S
Yip
Ashutosh
A
Singhal
Juliette
J
Hukin
D000293:Adolescent; D001932:Brain Neoplasms / Q000401:mortality / Q000601:surgery*; D002170:Canada; D002648:Child; D002675:Child, Preschool; D018672:Community Health Planning; D000071221:Enhancer of Zeste Homolog 2 Protein; D004806:Ependymoma / Q000401:mortality / Q000601:surgery*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D009493:Neurosurgery / Q000379:methods*; D063151:Polycomb Repressive Complex 2 / Q000378:metabolism; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies
D019394:Ki-67 Antigen; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2; D066246:ErbB Receptors