Isocitrate dehydrogenase type I mutation as a prognostic factor in glioblastoma and a literature review

Treatment response and prognosis in glioblastoma (GBM) tumours can differ among patients, highlighting the growing relevance of genetic biomarkers to differentiate glioblastoma sub-types. The biomarker isocitrate dehydrogenase (IDH1) is currently receiving considerable attention. The objective of this work was to analyse the clinical and prognostic differences between glioblastomas with and without the IDH1 mutation. A retrospective study was performed on patients with GBM who underwent surgery between 2007 and 2012. The inclusion criteria were: patient age between 18-85 years who underwent surgery for the first time with complete macroscopic resection, complete adjuvant treatment with chemotherapy and radiotherapy, and a Karnofsky performance score>70. A total of 61 patients (36 males/25 famales) were included and with a mean age of 62.3 years. An IDH1mutation was found in 14 patients (23%). Median survival in patients with the IDH1 mutation (IDH1-m) was 23.6 months compared with 11.9 months in those with the wild type IDH1 (IDH1-wt) (P=.028). Disease onset in IDH1-m patients tended to be at a younger age, 58.7 vs. 63.4 years, but this difference was not statistically significant. Glioblastomas with IDH1-m should be considered a different entity from the IDH1-wt, as their natural history and prognosis differ. In the near future we should be classified glioblastomas based on the presence of the IDH1 mutation.