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- Malmström, Annika, 1957-, et al.
(författare)
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Do we really know who has an MGMT methylated glioma? : results of an international survey regarding use of MGMT analyses for glioma
- 2020
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Ingår i: Neuro-Oncology Practice. - Oxford : Oxford University Press. - 2054-2577 .- 2054-2585. ; 7:1, s. 68-76
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Tidskriftsartikel (refereegranskat)abstract
- Background: Glioma O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status informs clinical decision making. Worldwide different methods and cutoff levels are used, which can lead to discordant methylation results.Methods: We conducted an international survey to clarify which methods are regularly used and why. We also explored opinions regarding international consensus on methods and cutoff.Results: The survey had 152 respondents from 25 countries. MGMT methylation status is determined for all glioblastomas in 37% of laboratories. The most common methods are methylation-specific polymerase chain reaction (msPCR) (37%) and pyrosequencing (34%). A method is selected for simplicity (56%), cost-effectiveness (50%), and reproducibility of results (52%). For sequencing, the number of CpG sites analyzed varies from 1–3 up to more than 16. For 50% of laboratories, the company producing the kit determines which CpG sites are examined, whereas 33% select the sites themselves. Selection of cutoff is equally distributed among a cutoff defined in the literature, by the local laboratory, or by the outside laboratory performing the analysis. This cutoff varies, reported from 1% to 30%, and in 1 laboratory tumor is determined as methylated in case of 1 methylated CpG site of 17 analyzed. Some report tumors as unmethylated or weakly vs highly methylated. An international consensus on MGMT methylation method and cutoff is warranted by 66% and 76% of respondents, respectively. The method preferred would be msPCR (45%) or pyrosequencing (42%), whereas 18% suggest next-generation sequencing.Conclusion: Although analysis of MGMT methylation status is routine, there is controversy regarding laboratory methods and cutoff level. Most respondents favor development of international consensus guidelines.
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| 2. |
- Malmström, Annika, 1957-
(författare)
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Studies for Better Treatment of Patients with Glioma
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden annually over 500 people will be diagnosed with the malignant brain tumor glioma. They are graded from I-IV. The majority are glioblastoma (grade IV) (GBM), these being the most aggressive type. Median survival for those treated with standard of care is expected to be around 15 months. This tumor will mainly affect those 60 years or older.The studies in this thesis focus on treatment of patients with malignant gliomas grade III and IV. The aim of the studies is to improve the care of glioma patients. Papers I and II explored different therapeutic options in randomized trials, to facilitate individualized treatment recommendations. Findings from studies I and II, together with additional trials, demonstrated the importance of analyzing the tumor marker O6-methylguanine DNA methyltransferase (MGMT) methylation status for survival of GBM patients treated with Temozolomide (TMZ). The third paper investigated how the analysis of this marker is implemented internationally.The first study (paper I, Nordic trial) investigated treatment options for patients 60 years or older with GBM. The trial compared standard radiotherapy (SRT) over 6 weeks versus hypofractionated radiotherapy (HRT) over 2 weeks versus single agent TMZ administered in up to six 4 weekly cycles. In all, 342 patients were included in the trial. This study demonstrated that those randomized to TMZ had superior survival as compared to SRT. In addition, quality of life (QoL) data also suggested a better QoL for TMZ treatment than for radiotherapy. The benefit of TMZ treatment seemed to be limited to those with the tumor molecular marker MGMT methylated (inactivated).The second trial (paper II, Neoadjuvant trial) studied whether integrating TMZ treatment with SRT for patients younger than 60 years with GBM (grade IV) and astrocytoma grade III would confer a survival benefit, if administered postoperatively, before the start of SRT (neoadjuvant). TMZ was provided for 2-3 four weekly cycles followed by SRT to patients randomized to neoadjuvant treatment and was compared to postoperative SRT alone. Although this trial could not illustrate any advantage of delaying the start of SRT while administering TMZ for the study cohort in general, for those included as astrocytoma grade III the median survival was found to be superior by 5 years when randomized to neoadjuvant TMZ. This trial also confirmed the importance of MGMT promoter methylation for the efficacy of TMZ.The third study (paper III) investigated international practices for analyzing tumor MGMT promoter methylation status. MGMT analysis can be conducted by various laboratory methods, which in some cases can provide opposing results regarding the MGMT methylation status of the patient´s tumor. This can lead to incorrect treatment recommendations. To establish which methods and cut-offs that are regularly used to determine tumor MGMT status in the clinic, an international survey was provided to those working in the field. We also inquired about opinions regarding an international consensus on how MGMT should be tested. The 152 respondents reported several methodologies and different cut-off levels also for the same method. A majority of respondents warrant international guidelines.In conclusion, the results of the 2 randomized trials contribute to individualized treatment recommendations for patients affected by GBM or astrocytoma grade III. The results of the survey regarding analyses of MGMT clarify the current problematic situation. The request of the respondents regarding international guidelines might contribute to their future development, so that personalized treatment recommendations can be improved.
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