Abstract 378P
Background
WHO grade III gliomas are classified according to the presence of IDHmutation.IDH wild type (IDH wt) is associated with poor prognosis and limited effectiveness of treatments. The aim of this study was to find out if MGMT methylation represents a prognostic factor in this setting.
Methods
We analyzed our Institutional data warehouse for all consecutive patients (pts) with newly diagnosed, histologically proven grade III, IDH wt gliomas. IDH 1/2 assessment was performed by Next Generation Sequencing (NGS). MGMT methylation was assessed by methylation specific PCR (MSP). Tissue samples were also centrally reviewed for histology.
Results
The analysis included 73 pts with grade III, IDH wt (19.3%) gliomas. Median follow-up time was 69.9 months. Median age was 50 (Range: 18-75), M/F ratio was40(54.8%)/33(45.2%),.MGMT promoter was methylated in 34 pts (46.6%) and unmethylated in 39 pts (53.4%).After surgery, 9 pts (12.3%) received RT alone, 57 pts (78.1%) received both RT and CT (sequential, concomitant or both). Median survival was 26.2 months. In multivariate analysis age (HR=1.064, 95%CI: 1.030-1.099; P<0.001) and MGMT methylation (HR=0.422, 95%CI: 0.210-0.848; P=0.015) were independently associated with risk for death.
Conclusions
IDH wild type confers a dismal prognosis in patients with grade III glioma. MGMT methylation, as was demonstrated in glioblastoma, represents a prognostic factor that correlated with a reduced risk of death. Further studies will investigate potential correlations with treatments.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.