Prognostic factors for glioblastoma: a retrospective single-center analysis of 176 adults

To explore the clinical features, treatment and prognosis of glioblastomas (GBM) in adults.

A retrospective cohort study was performed on 176 adult GBM patients admitted to our department from January 2015 to December 2021. Chi-square test was used to investigate the clinical differences between isocitrate dehydrogenase (IDH) mutant and wild-type GBM. Kaplan-Meier and Log-Rank tests were employed to plot survival curve and compute the survival analysis. Multivariate Cox regression model was applied to identify the independent prognostic factors.

IDH wild-type GBM account for 89.2% and had significantly differences from the IDH-mutant GBM in terms of age of onset, Karnofsky (KPS) score at admission, symptoms of neurological deficit, and methylation status of O⁶-methylguanine-DNA-methyltransferase (MGMT) promoter (P<0.05). For the IDH wild-type GBM patients receiving conventional therapy, univariate Cox hazard analysis showed gross total resection, methylation of MGMT promoter, initiation of radiation within the 5th to 6th week after surgery, and adjuvant temozolomide (TMZ) chemotherapy ≥6 cycles were favorable prognostic factors for overall survival (OS); GBMs in the left hemisphere, involvement of single lobe, methylation of MGMT promoter, and initiation of radiation within the 5th to 6th week after surgery were favorable prognostic factors for progression free survival (PFS) (all P<0.05). Moreover, multivariate Cox hazard regression analysis indicated that methylation of MGMT promoter, and initiation of radiation within the 5th to 6th week after surgery, and adjuvant TMZ chemotherapy ≥6 cycles were independent protective factors for OS, and GBMs in the left hemisphere, involvement of single lobe and methylation of MGMT promoter were independent protective factors for PFS in the GBM patients (all P<0.05).

The clinical and prognostic features are totally different between IDH mutant and wild-type GBM, and molecular detections are needed for the further pathological classification. Methylation of MGMT promoter is a primary marker of favorite prognosis for IDH wild-type GBM, and slightly delay in radiotherapy (the 5th to 6th week after surgery) can effectively improve the survival prognosis of IDH wild-type GBM.