News Story: Full Text
Sponsored By
Cedars-Siani Medical Center Brain Tumor Program
Please Click On The Above Banner For More Details
Braintumor Website

 

Anti-O6-Methylguanine-Methyltransferase (MGMT) Immunohistochemistry in Glioblastoma Multiforme: Observer Variability and Lack of Association with Patient Survival Impede Its Use as Clinical Biomarker.


Posted on: 04/27/2008

Brain Pathol. 2008 Apr 8; [Epub ahead of print]


Anti-O6-Methylguanine-Methyltransferase (MGMT) Immunohistochemistry in Glioblastoma Multiforme: Observer Variability and Lack of Association with Patient Survival Impede Its Use as Clinical Biomarker.

Preusser M, Janzer RC, Felsberg J, Reifenberger G, Hamou MF, Diserens AC, Stupp R, Gorlia T, Marosi C, Heinzl H, Hainfellner JA, Hegi M.

Department of Internal Medicine 1, Medical University of Vienna, Vienna, Austria.

Silencing of O6-methylguanine-DNA methyltransferase (MGMT) protein expression because of MGMT gene promoter hypermethylation is considered to be associated with postoperative chemoradiotherapy benefits in glioblastoma multiforme (GBM) patients. The objective of this study was to clarify the usability of MGMT immunohistochemistry (IHC) as a clinical biomarker. We immunostained a tissue microarray containing biopsy samples of 164 GBM patients from the European Organization for Research and Treatment of Cancer and the National Cancer Institute of Canada (EORTC/NCIC) trial 26981/22981 using two commercial anti-MGMT antibodies (clones MT3.1 and MT23.2). Immunostaining results were semiquantitatively evaluated by four observers from three neuropathological laboratories using a predefined algorithm. We analyzed (i) inter- and intraobserver agreement on MGMT expression (kappa statistics); (ii) correlation of MGMT expression with MGMT promoter methylation status (kappa statistics); and (iii) correlation of MGMT expression with patient outcome (log-rank test). Interobserver agreement on MGMT expression varied from slight to almost perfect, whereas intraobserver agreement ranged from substantial to almost perfect. MGMT expression showed poor to moderate correlation with MGMT promoter methylation status. We found no significant association of MGMT expression with patient outcome. In our hands, observer variability as well as lack of association with the MGMT promoter methylation status and patient survival impeded the use of anti-MGMT immunohistochemistry as a clinical biomarker for routine diagnostic purposes.

PMID: 18400046 [PubMed - as supplied by publisher]

Click HERE to return to brain tumor news headlines


Home | Brain Tumor Guide | FAQs | Find A Treatment
Noteworthy Treatments | News | Virtual Trial | Videos | Novocure Optune® | Newsletter
Donations | Brain Tumor Centers | Survivor Stories | Temodar®
Fundraising For Research | Unsubscribe | Contact Us

Copyright (c) 1993 - 2019 by:
The Musella Foundation For Brain Tumor Research & Information, Inc
1100 Peninsula Blvd
Hewlett, NY 11557
888-295-4740