gms | German Medical Science

Objective: Although mean survival time of patients with glioblastoma multiforme is about 12 months, there are 3-5% of patients having a long-term survival of longer than 36 months. To date, little is known about the clinical and molecular characteristics of that special group of patients. It is of interest to investigate whether there are clinical or molecular factors distinguishing this particular subgroup from patients with an average course. In our study, we performed an extensive characterization of 59 glioblastoma long-term survivors, which is, to our knowledge, the largest published series.

Methods: Patients have been recruited in all six clinical centres comprising the German Glioma Network and one associated centre. All patients with a diagnosis of glioblastoma multiforme have been identified in each data base of a single department. After reconfirmation of the diagnosis by the German Brain Tumor Reference centre, patients were included and a standardized evaluation form for demographic, clinical, and treatment-based parameters was completed. In addition, environmental risk factors, associated diseases, and occupational risks were evaluated. Molecular analysis of tumor samples was performed, comprising p53 mutation, EGFR amplification, 1p/19q loss and MGMT promoter methylation status.

Results: The study group comprised 59 patients (male=29; female=30, median age 51 years). There were 55 primary and 4 secondary glioblastoma, originating from grade II astrocytoma (3 patients) and grade II oligoastrocytoma (1 patient). Mean survival time after diagnosis of glioblastoma was 5.9 years (range 3.0 – 15.0 years). Clinical characteristics and treatment modalities of all patients will be presented. MGMT promoter methylation was found in 65% of all tumors, The absolute numbers of patients with p53 mutation and EGFR amplification was comparable with those in general gliblastoma samples. Analysis for 1p/19q confirmed that the study population consisted of tumors of glial origin.

Conclusions: This is the largest sample of glioblastoma long-term survivors published so far. All patients were treated by an intensive multimodal approach including intended gross total resection, radiotherapy and chemotherapy. Single clinical and socioeconomic parameters failed to show a significant association with survival. The positive predictive value of MGMT promoter methylation is discussed.