Long-term survival in glioblastoma: methyl guanine methyl transferase (MGMT) promoter methylation as independent favourable prognostic factor
Categoria dell'articolo: Research Article
Pubblicato online: 10 nov 2016
Pagine: 394 - 401
Ricevuto: 15 lug 2015
Accettato: 06 ago 2015
DOI: https://doi.org/10.1515/raon-2015-0041
Parole chiave
© 2016 Radiol Oncol
This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background
In spite of significant improvement after multi-modality treatment, prognosis of most patients with glioblastoma remains poor. Standard clinical prognostic factors (age, gender, extent of surgery and performance status) do not clearly predict long-term survival. The aim of this case-control study was to evaluate immuno-histochemical and genetic characteristics of the tumour as additional prognostic factors in glioblastoma.
Patients and methods
Long-term survivor group were 40 patients with glioblastoma with survival longer than 30 months. Control group were 40 patients with shorter survival and matched to the long-term survivor group according to the clinical prognostic factors. All patients underwent multimodality treatment with surgery, postoperative conformal radiotherapy and temozolomide during and after radiotherapy. Biopsy samples were tested for the methylation of MGMT promoter (with methylation specific polymerase chain reaction), IDH1 (with immunohistochemistry), IDH2, CDKN2A and CDKN2B (with multiplex ligation-dependent probe amplification), and 1p and 19q mutations (with fluorescent
Results
Methylation of MGMT promoter was found in 95% and in 36% in the long-term survivor and control groups, respectively (p < 0.001). IDH1 R132H mutated patients had a non-significant lower risk of dying from glioblastoma (p = 0.437), in comparison to patients without this mutation. Other mutations were rare, with no significant difference between the two groups.
Conclusions
Molecular and genetic testing offers additional prognostic and predictive information for patients with glioblastoma. The most important finding of our analysis is that in the absence of MGMT promoter methylation, longterm survival is very rare. For patients without this mutation, alternative treatments should be explored.