Sex‐related Survival Differences in Patients With Glioblastoma – Results From a Retrospective Analysis

Background/Aim: Glioblastoma is more common in men than in women. The aim of this analysis was to investigate sex‑ specific differences with a particular focus on their impact on survival including overall survival (OS) and progression‑free survival (PFS). Patients and Methods: This retrospective study analyzed 209 GBM patients (91 females, 118 males) treated according to the Stupp regimen. Data on patient demographics, O6‑methylguanine‑DNA methyltransferase (MGMT) methylation status, treatment details [radiotherapy (RT) doses and temozolomide (TMZ) cycles], and survival endpoints were statistically analyzed using univariable Kaplan‑Meier [and 95% confidence intervals (CI)] and multivariable Cox regression hazards models. Results: In the whole cohort, median follow‑up was 14 (2‑119) months. We observed a trend towards a higher prevalence of multifocal tumors in males (30.5% vs. 22%, p=0.092). In univariable analysis, MGMT‑negative male patients who received >58 Gy RT had a significantly longer OS (14 vs. 5 months, log‑rank p<0.001). In multivariable analysis, OS was not significantly influenced by patient age (p=0.579), total RT dose (Gy) (p=0.348), and MGMT status (p=0.262). Female patients (HR=3.252, p=0.028) and patients with higher tumor volume (HR=1.031, p=0.005) had a significantly higher mortality risk. Better Karnofsky‑performance‑status (HR=0.918, p=0.008), complete resection (HR=6.759, p=0.022), and higher numbers of adjuvant TMZ cycles (HR=0.739, p=0.003) led to prolonged OS. Conclusion: Sex seems to impact survival in patients suffering from glioblastoma, although underlying mechanisms are not yet completely understood. Treatment intensity (complete resection and the maximum possible number of TMZ cycles) had a significant effect on the patients’ mortality risk.