'The Reports of My Death Are Greatly Exaggerated'-Evaluating the Effect of Necrosis on MGMT Promoter Methylation Testing in High-Grade Glioma

Laveniya Satgunaseelan; Maggie Lee; Sebastian Iannuzzi; Susannah Hallal; Kristine Deang; Kristian Stanceski; Heng Wei; Sofia Mason; Brindha Shivalingam; Hao-Wen Sim; Michael E Buckland; Kimberley L Alexander

doi:10.3390/cancers16101906

'The Reports of My Death Are Greatly Exaggerated'-Evaluating the Effect of Necrosis on MGMT Promoter Methylation Testing in High-Grade Glioma

Cancers (Basel). 2024 May 16;16(10):1906. doi: 10.3390/cancers16101906.

Authors

Laveniya Satgunaseelan^{1

2}, Maggie Lee^{1

2}, Sebastian Iannuzzi^{1

2}, Susannah Hallal^{1

2

3}, Kristine Deang^{2

3}, Kristian Stanceski^{1

2}, Heng Wei^{1

2}, Sofia Mason^{4

5

6}, Brindha Shivalingam^{2

3

7}, Hao-Wen Sim^{4

5

6

8

9}, Michael E Buckland^{1

2}, Kimberley L Alexander^{1

2

3}

Affiliations

¹ Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia.
² Faculty of Medicine and Health, School of Medicine, University of Sydney, Camperdown Campus, Sydney, NSW 2000, Australia.
³ Department of Neurosurgery, Chris O'Brien Lifehouse, Camperdown, NSW 2050, Australia.
⁴ Department of Medical Oncology, Chris O'Brien Lifehouse, Camperdown, NSW 2050, Australia.
⁵ Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia.
⁶ Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia.
⁷ Department of Neurosurgery, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia.
⁸ NHMRC Clinical Trials Centre, University of Sydney, Camperdown, NSW 2050, Australia.
⁹ Department of Medical Oncology, The Kinghorn Cancer Centre, Darlinghurst, NSW 2010, Australia.

Abstract

(1) Background: MGMT (O-6-methylguanine-DNA methyltransferase) promoter methylation remains an important predictive biomarker in high-grade gliomas (HGGs). The influence of necrosis on the fidelity of MGMT promoter (MGMTp) hypermethylation testing is currently unknown. Therefore, our study aims to evaluate the effect of varying degrees of necrosis on MGMTp status, as determined by pyrosequencing, in a series of primary and recurrent HGGs; (2) Methods: Within each case, the most viable blocks (assigned as 'true' MGMTp status) and the most necrotic block were determined by histopathology review. MGMTp status was determined by pyrosequencing. Comparisons of MGMTp status were made between the most viable and most necrotic blocks. (3) Results: 163 samples from 64 patients with HGGs were analyzed. MGMTp status was maintained in 84.6% of primary and 78.3% of recurrent HGGs between the most viable and necrotic blocks. A threshold of ≥60% tumor cellularity was established at which MGMTp status was unaltered, irrespective of the degree of necrosis. (4) Conclusions: MGMTp methylation status, as determined by pyrosequencing, does not appear to be influenced by necrosis in the majority of cases at a cellularity of at least 60%. Further investigation into the role of intratumoral heterogeneity on MGMTp status will increase our understanding of this predictive marker.

Keywords: MGMT promoter; astrocytoma; glioblastoma; glioma; necrosis.

Grants and funding

Funding support was received from the NSW Ministry of Health, Chris O’Brien Lifehouse Brain Cancer Research Fund, Brainstorm, BF Foundation and Cure My Brain.