Clinicopathological, immunohistochemical and therapeutic approaches on survival in patients with epithelioid glioblastoma: Institutional experience in the management of 58 patients

Epithelioid glioblastoma (Ep-GBM) is a rare variant of glioblastoma characterized by a high recurrence rate and poor prognosis. Currently, there is no established standard treatment for Ep-GBM. Therefore, we identified 58 Ep-GBM cases to investigate these characteristics and identify the possible prognostic factors of survival. There were 30 male and 28 female patients with a median age of 39 years. Headaches and dizziness were the most common clinical symptom. The tumor is most frequently located in the temporal lobe (36.2%). The positivity rate for BRAF-V600E is 56.9% (33/58), for MGMT is 56.9% (33/58), and for INI-1 is 75% (30/40). Tumor recurrence was observed in 39 patients. The median progression-free survival (PFS) of all patients was 12.7 months, while the median overall survival (OS) was 29.1 months. Additionally, the median survival time after recurrence was 14.3 months. Both univariate and multivariate COX regression analyses revealed that individuals who received more than six cycles of adjuvant oral temozolomide experienced a longer median PFS compared to those who received fewer cycles. Characteristics associated with poorer PFS included tumor dissemination prior to initial surgery. Additionally, both analyses identified tumor dissemination, radiotherapy and adjuvant oral temozolomide as predictors of OS. Notably, for patients with recurrent Ep-GBM, reoperation was shown to significantly increase survival time after recurrence. In conclusion, the standard Stupp regimen is also applicable to patients with Ep-GBM, extending adjuvant oral temozolomide could further improve survival for Ep-GBM patients, reoperation may also prolong survival for recurrent Ep-GBM.