Analysis of Patients with Glioblastoma Treated with Standard 6-Week Chemoradiation Followed by Temozolomide: Treatment Outcomes and Prognostic Factors

<i>Background and Objectives</i>: We aimed to investigate the treatment outcomes and prognostic factors of survival among patients with glioblastoma who underwent 6-week concurrent chemoradiation therapy (CCRT) followed by temozolomide (TMZ) with Stupp's regimen in a single tertiary institution. <i>Materials and Methods</i>: Eighty patients with glioblastoma who underwent 6-week CCRT followed by TMZ between June 2010 and January 2024 were retrospectively investigated. A survival analysis was performed of factors such as age, O (6)-methylguanine-DNA methyltransferase promoter (MGMT) methylation, extent of resection, pre- and post-operative Karnofsky Performance Status, and inflammatory markers such as neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio. Post-operative inflammatory markers were assessed at 2-3 weeks post-operative before the initiation of CCRT. A subgroup analysis was performed of patients who underwent non-gross total resection (GTR). <i>Results</i>: The median progression-free survival (PFS) and overall survival (OS) of the entire cohort were 8.97 months and 19.0 months, respectively. Older age (≥65 years) and non-GTR status were adverse prognostic factors of PFS and OS. MGMT methylation is a favorable prognostic factor for PFS and OS. In the subgroup of patients who underwent non-GTR, MGMT methylation and post-operative LMR (<3.2/>3.2) were independent prognostic factors for PFS and OS. <i>Conclusions</i>: As with previous studies, older age, MGMT methylation, and extent of resection were independent prognostic factors for the survival of patients with glioblastoma who underwent standard treatment with Stupp's regimen. MGMT methylation and post-operative LMR were significant prognostic factors for PFS and OS among patients who underwent non-GTR. The prognostic significance of post-operative inflammatory markers for treatment response and survival should be further validated in glioblastoma patients treated with Stupp's regimen.