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Pediatr Blood Cancer 2009;52:65–69
Both Location and Age Predict Survival in Ependymoma: A SEER Study
Courtney S. McGuire, MD,1 Kristin L. Sainani, PhD,2 and Paul Graham Fisher, MD
1,3,4,5*
INTRODUCTION
Brain tumors currently occur at an annual rate reported as high as
4.3 per 100,000 person-years in children, with ependymomas
comprising 8–10% of these neoplasms [1–7]. Ependymoma
continues to be associated with significant mortality with 5-year
overall survival reported about 65% [6,8]. Opinions vary regarding
which factors influence outcome.
Younger children are generally thought to have a poorer
prognosis [9,10], and survival rates appear to be lower in children
than adults [6]. Although radiotherapy is the standard of care for
adults, current treatment recommendations for children vary and
are often limited by the significant neurotoxicity associated with
radiation [11]. Survival has also been reported to vary by tumor
location: supratentorial tumors lead to higher survival rates than
infratentorial tumors, and spinal tumors have the best prognosis [1–
3,12].
Unfortunately, many studies reporting these survival trends are
based on small samples and single-institution experiences. Thus,
there is a need for more complete and definitive analysis based upon
a larger sample in a population-based cancer registry. This study
sought to analyze how age, gender, location, race, and radiotherapy
influence survival in ependymoma, using such a comprehensive
database.
METHODS
The Surveillance Epidemiology End Results Program (SEER-17)
was used to identify all ependymoma cases diagnosed at age 18 or
younger in 17 United States cancer registries from 1973 to 2003 [13].
The National Cancer Institute’s SEER database is an authoritative
source of United States population-based data, incorporating both
historical and current cases, and now draws a representative 26% of
the population [13]. Approval for research was granted by the
Stanford Panel on Human Subjects in Medical Research. Cases were
selected from the SEER-17 if there was a diagnosis of ependymoma
defined by the International Classification of Disease (ICD-0-3)
histology codes 9391, 9392, 9393, and 9394 (ependymoma, ana-
plastic ependymoma, papillary ependymoma and myxopapillary
ependymoma). The SEER database captures institutional diagnoses
and does not centrally review pathology. Primary tumor locations
were distinguished by ICD-0-2 site codes and defined as supraten-
torial (700, 702–714), infratentorial (716-717), or spinal (720-721,
701, 725). Those tumors identified as ventricle, overlapping
brain, brain not otherwise specified, overlapping or not otherwise
specified (715, 718, 719, 728, and 729) were excluded from location
analysis because of the inability to assign the tumor to one of the three
strata.
Survival was defined as the time fromdiagnosis until death due to
all causes. Overall survival was calculated by Kaplan–Meier
analysis. Treatments coded as beam radiation, radioactive, and
radiation were classified as ‘‘radiotherapy’’ while those labeled as
none or refused were classified as ‘‘no radiotherapy.’’ Outcomes
were compared by age, location, gender, race (blacks and whites),
and radiotherapy using univariate logrank tests.
Cox proportional hazards multivariate regression was subse-
quently used to incorporate all significant covariates from univariate
analysis (i.e., location, age, radiotherapy). A pre-planned multi-
variate analysis was completed for the subgroup of infratentorial
tumors incorporating the significant univariate covariates age and
Background. Studies have suggested that supratentorial ependy-
momas have better survival than infratentorial tumors, with spinal
tumors having the best prognosis, but these data have been based on
small samples. Using a population-based registry of ependymomas,
we analyzed how age, gender, location, race and radiotherapy
influence survival in children. Methods. We queried the Surveillance
Epidemiology End Results database (SEER-17) from 1973 to 2003,
strictly defining ependymomas by histology. Site codes were used to
distinguish between supratentorial, infratentorial, and spinal tumors
when available. Outcomes were compared by location, age, gender,
race and radiotherapy, using Kaplan–Meier analysis and logrank
tests. Cox regression was completed, incorporating all significant
covariates from univariate analysis. Results. Six hundred thirty-five
children were identified with an overall 5-year survival of
57.1 standard error (SE) 2.3%. Increasing age was associated with
improved survival (P< 0.0001). Five-year survival by location was
59.5 SE 5.5% supratentorial, 57.1 SE 4.1% infratentorial and
86.7 SE 5.2% spinal. Radiotherapy of the infratentorial tumors
resulted in significantly improved survival in both univariate analysis
(logrank P < 0.018) and multivariate analysis restricted to this tumor
location (P ¼0.033). Using multivariate analysis that incorporated all
tumor locations, age (P < 0.001) and location (P¼ 0.020) were
significant predictors for survival. Conclusions. Age and location
independently influence survival in ependymoma. Spinal tumors are
associated with a significantly better prognosis than both supra-
tentorial and infratentorial tumors, and may represent a distinct
biological entity. Radiotherapy appears beneficial for survival in
patients with infratentorial ependymoma. Pediatr Blood Cancer
2009;52:65–69. 2008 Wiley-Liss, Inc.
Key words: brain tumor; ependymomas; epidemiology; pediatric oncology; survival
2008 Wiley-Liss, Inc.
DOI 10.1002/pbc.21806
Published online in Wiley InterScience
)
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1Department of Neurology, Stanford University, Palo Alto, California;
2Department of Health Research and Policy, Stanford University, Palo
Alto, California; 3Department of Pediatrics, Stanford University, Palo
Alto, California; 4Department of Neurosurgery, Stanford University,
Palo Alto, California; 5Department of Human Biology, Stanford
University, Palo Alto, California
This work was presented in part at the 2007 Annual Meeting of the
American Society of Clinical Oncology, Chicago, Illinois, June 6,
2007.
*Correspondence to: Paul Graham Fisher, Room CC22200, Stanford
Cancer Center, 875 Blake Wilbur Drive, Palo Alto, CA 94305-5826.
E-mail:
Received 29 February 2008; Accepted 9 September 2008