Epilepsy as primary tumor manifestation correlates with patient status, age, and tumor volume but not with survival in elderly glioblastoma patients: a retrospective bicentric analysis.

Assessment of the potential impact of epilepsy as primary tumor manifestation on survival in elderly glioblastoma multiforme (GBM) patients. Two academic neurosurgical centers retrospectively analyzed all GBM patients aged 65 years and older with de-novo tumors, who underwent surgery between 2006 and 2021. Epidemiological, histopathological, imaging and survival data were obtained from patients' electronic charts, and screened for the presence of epilepsy preoperatively and during follow-up. Patient status was assessed by the Karnofsky Performance Scale (KPS), epilepsy was evaluated using the Engel classification. Patients were categorized in an epilepsy cohort (i.e. patients with epilepsy as primary GBM manifestation, and a reference cohort (i.e. patients with no initial epilepsy). This study analyzed 451 GBM patients (55% males); median age at tumor diagnosis was 73 years. The epilepsy cohort was younger (71.0 vs. 74.0 year; p = 0.001), had better KPS (80 vs. 70; p = 0.039), and had smaller tumors (127 vs. 221 cm³; p = 0.001) compared to the reference cohort. There were no differences with regard to neurosurgical treatment (i.e. resection vs. biopsy), tumor biomarkers, surgery-associated complications, and performed adjuvant treatment (all p > 0.05). We did not detect a significant difference in median survival between the epilepsy and reference cohorts (8 vs. 6 months; p = 0.21). New epilepsy during follow-up often coincided with tumor recurrence/progression, but also did not significantly affect survival. The majority of patients (98%) achieved seizure freedom by a combination of tumor-specific treatments and antiseizure medication. Epilepsy as primary tumor manifestation does not correlate with survival in elderly GBM patients.