gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Intratumoral patterns of clonal evolution in meningiomas

Intratumorale genetische Muster klonaler Entwicklungsstufen in Meningeomen

Meeting Abstract

  • corresponding author R. Ketter - Department of Neurosurgery, Saarland University, Homburg/Saar
  • J. Rahnenführer - Max-Planck-Institute for Informatics, Saarbrücken
  • W. Henn - Institute of Human Genetics, Saarland University, Homburg/Saar
  • S. Wemmert - Department of Neurosurgery, Saarland University, Homburg/Saar
  • Y.J. Kim - Department of Neuropathology, Saarland University, Homburg/Saar
  • K.D. Zang - Institute of Human Genetics, Saarland University, Homburg/Saar
  • S. Urbschat - Department of Neurosurgery, Saarland University, Homburg/Saar
  • W.I. Steudel - Department of Neurosurgery, Saarland University, Homburg/Saar

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 06.78

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2006/06dgnc295.shtml

Published: May 8, 2006

© 2006 Ketter et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: Meningioma is the most frequent tumor of neuroectodermal origin in humans and is usually benign. However, meningiomas show an unexpectedly high recurrence rate. It is one of the cytogenetically best-studied solid tumors. Most of the tumors show either monosomy 22 or a diploid karyotype. Progression of meningiomas is correlated with increasing hypodiploidy (loss of chromosomes 14, 18, 19, 6, 10) and structural aberration (loss of the short arm of chromosome 1) showing characteristic clonal evolutions.

Methods: 661 patients in which tumor resections were determined to be Simpson Grade I or II could be followed up after complete tumor exstirpation from 1973 to 2004. On the basis of the cytogenetic findings, the meningiomas were subdivided into four groups. Group 0 meningiomas display a normal karyotype, group 1 tumors only show monosomy 22, group 2 tumors are meningiomas with monosomy 22 and additional chromosomal losses, and group 3 meningiomas have deletions of the short arm of a chromosome 1, as well as additional chromosomal aberrations including loss of one chromosome 22.

Results: In 8.0% (53/649) of the tumors that belong to one of the four cytogenetically defined groups, one or several recurrences were documented during the period of observation. We detected a clear correlation between cytogenetic findings and recurrencies of meningiomas. Recurrences were found in 8.1% (25/308) of tumors in group 0, in 3.7% (8/216) of tumors in group 1, and in 5.0% (3/60) of tumors in group 2. The highest rate of recurrence was found in group 3 with 26.2% (17/65) of the tumors. The results of this study document a significant correlation between the cytogenetic classification and recurrence (p<0.001), location of the tumor (p<10-5), and WHO grade (p<10-15). Therefore cytogenetic classification of meningiomas provides a significant contribution to the predictability of tumor recurrence and is a valuable parameter for the postoperative management protocol.

Conclusions: With an oncogenetic trees mixture model the most likely order of cytogenetic aberrations was estimated. The estimated model agrees with a priori knowledge and can be used to assign a genetic progression score (GPS) to single tumors. The GPS of a tumor is a quantitative measure and allows a more precise assessment of genetic progression than the categorical cytogenetic classification.