A Comparison of <i>MGMT</i> Testing by MSP and qMSP in Paired Snap-Frozen and Formalin-Fixed Paraffin-Embedded Gliomas
Milica Lazarević,
Nikola Jovanović,
Vladimir J. Cvetković,
Svetlana Tošić,
Jelena Vitorović,
Slaviša Stamenković,
Vesna Nikolov,
Nataša Vidović,
Jelena Kostić Perić,
Marija Jovanović,
Tatjana Mitrović
Affiliations
Milica Lazarević
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Nikola Jovanović
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Vladimir J. Cvetković
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Svetlana Tošić
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Jelena Vitorović
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Slaviša Stamenković
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Vesna Nikolov
Faculty of Medicine, Clinic of Neurosurgery, Clinical Centre, University of Niš, 18000 Niš, Serbia
Nataša Vidović
Faculty of Medicine, Pathology and Pathological Anathomy Centre, Clinical Centre, University of Niš, 18000 Niš, Serbia
Jelena Kostić Perić
Laboratory for Molecular Biomedicine, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11042 Belgrade, Serbia
Marija Jovanović
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Tatjana Mitrović
Laboratory for Molecular Biology and Biotechnology, Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, 18000 Niš, Serbia
Comparative analysis of the conventional methylation-specific PCR (MSP) vs. the quantitative MSP (qMSP) assessment of the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in 34 snap-frozen (SF) glioma samples was performed. The accuracy of the semi-quantitative MSP was compared with the corresponding qMSP semi-quantitative values using two semi-quantitative cut-off values (0—unmethylated and 1—weakly methylated) to discriminate methylated from unmethylated samples. In the case of the cut-off value 0, MSP test showed 80.0% sensitivity and 78.9% specificity compared to the reference qMSP analysis. However, when using the cut-off value 1, the diagnostic accuracy of the MSP test was significantly higher (85.7% sensitivity, 85.2% specificity). Fleiss’ Kappa statistical analyses indicated moderate agreement (Fleiss’ Kappa Coefficient = 0.509; 70.59% agreement) between MSP and qMSP semi-quantitative measurements of MGMT promoter methylation in glioma patients, justifying the conventional MSP use in diagnostics and confirming its high reliability. Further, we aimed to compare the validity of SF and formalin-fixed paraffin-embedded (FFPE) glioma samples for MGMT testing. Statistical analyses indicated moderate overall agreement of FFPE glioma samples and SF MSP semi-quantitative measurements (Fleiss’ Kappa Coefficient = 0.516/0.509; 70.0% agreement) and emphasized their low reliability in the assessment of highly methylated MGMT promoter samples.
