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Inverse correlation between genetic
aberrations and malignancy grade in ependymal tumors: a paradox?
Gilhuis HJ, van der Laak J, Wesseling P, Boerman RH, Beute G, Teepen JL,
Grotenhuis JA, Kappelle AC
Department of Neurology, University Medical Center St Radboud,
Nijmegen, The Netherlands. h.gilhuis@czzoneu.umcn.nl
Objective. The goal of our study was to investigate the inverse
correlation between number of genetic aberrations and malignancy grade in
ependymal tumors at the ploidy level.
Methods. We examined seven myxopapillary ependymomas (mpEs) (WHO grade
I), 28 spinal and cerebral ependymomas (Es) (WHO grade II), and 18 cerebral
anaplastic ependymomas (aEs) (WHO grade III) using image DNA cytometry.
The ploidy status was correlated with clinicopathological characteristics and
with the results obtained by comparative genomic hybridization (CGH) analysis
that we performed in about half of these tumors.
Results. mpEs were exclusively located in the spinal cord and aEs in
the cerebrum only, whereas Es were located in both the spinal cord and
brain.
We found aneuploidy or tetraploidy to be common in the group of mpEs (6 out of
7) and much less frequent in Es (6 out of 28) and aEs (4 out of 18).
Three-year postoperative survival was 100% for mpEs, 100% for spinal Es, 92% for
cerebral Es, and 33% for aEs.
Our CGH results in a selection of these tumors revealed the highest number of
genetic aberrations in the mpEs (average 16; n = 2), a lower number in Es
(average 12; n = 11) and the lowest number in aEs (average 5; n = 6).
Interestingly, in the group of Es and aEs, a high number of genetic aberrations
as detected by CGH was not correlated with aneuploidy or tetraploidy.
Three patients, all with mpEs had local seeding.
Conclusion. These results underline that mpEs are distinctly different
from Es and aEs at the genetic level and that extensive genomic alterations and
aneuploidy in ependymal tumors are not in itself an indicator of malignant
behavior.
PMID: 15015776 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15015776
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