gms | German Medical Science

Objective: Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. Demographic development has increased the rate of newly diagnosed glioblastoma multiforme in elderly patients (>65 years). The standard therapy of GBM includes surgical resection followed by a MGMT-promoter stratified adjuvant radio- or chemotherapy. The aim of this study was evaluate the functional and oncological outcome in elderly patients treated by different therapy strategies included surgical re-resection in the case of tumor recurrence.

Methods: This is a single-center retrospective analysis including all surgically treated GBM patients older than 65 years. Comprehensive data concerning overall survival, progression free survival, different treatment modalities, functional outcome (NANO) and Karnofsky index (KPI) have been collected and analyzed. Survival analysis was performed by Cox-regression model included a 10-fold cross-validation. The alpha-level was determined to 5% to achieve statistical significance with a power of 80%. Cut-off values for age depended deficits were calculated by ROC analysis and a logit regression model.

Results: A total of 128 elderly patients with glioblastoma multiforme have been evaluated. The median overall survival (OS) was 6.8 months with a median progression free survival 5.5 months. Mean age at diagnosis was 73.5 years and the mean postoperative KPI was 75. A total of 96 patients underwent surgical resection, whereas the remaining 32 cases had a stereotactic biopsy. The postoperative treatment included combined radiochemotherapy in 36 patients, chemotherapy alone in 10, radiotherapy alone 23 patients. The patients with combined radiochemotherapy had longer overall survival compared to those with either radio or chemotherapy alone (HR 0.1 p<0.01). Patients (n=28), who underwent more than one resection because of recurrent disease, had a significant longer overall survival compared to those, who had only one surgical treatment (HR 0.5 p=0.016). Multivariate analysis revealed gross total resection and combined radiochemotherapy as independent prognostic factors associated with significant longer OS. A logit regression model showed a significant increase of postoperative neurological impairment (NANO > 2) beyond the age of 78 years.

Conclusion: Surgical treatment of recurrent glioblastoma multiforme in elderly patients is possible and can result in good functional outcome with mean KPI of 75. Gross total resection followed by adjuvant radiochemotherapy can increase the progression-free and overall free of elderly patients. Elderly patients may profit from an extended surgical and adjuvant treatment with an acceptable functional outcome. Particularly with regard to an increased risk of postoperative deficits, surgical treatment needs to be carefully and individually evaluated in patients beyond the age of 78 years.