Title : Real-world outcomes in glioblastoma: A retrospective single-center cohort analysis
Abstract:
Purpose/Objective(s): Glioblastoma (GBM) remains associated with poor prognosis despite multimodality treatment. Real-world cohorts may provide complementary evidence regarding outcomes outside highly selected clinical trial populations. We evaluated clinical characteristics, treatment patterns, and survival outcomes in a retrospective cohort of patients with GBM treated at a tertiary oncology center.
Materials/Methods: We retrospectively reviewed 50 consecutive adult patients with newly diagnosed WHO grade 4 glioblastoma treated between 2016 and 2025. Clinical, radiological, surgical, and treatment-related variables were collected from institutional records. Overall survival (OS) was defined from diagnosis to death or last follow-up, and progressionfree survival (PFS) from diagnosis to radiological or clinical progression, death, or censoring. Patients alive without progression were censored on May 15, 2026. Survival was estimated using the Kaplan–Meier method. Exploratory multivariable Cox regression analyses included age at diagnosis, Karnofsky Performance Status (KPS), extent of resection, multifocal disease, and largest lesion diameter on MRI.
Results: The cohort included 50 patients with a median age of 56 years. Multifocal disease was present in 40% of cases, and the median largest lesion diameter on MRI was 5.0 cm. Gross total resection was achieved in 20% of patients, subtotal resection in 66%, and biopsy only in 14%. KPS was ≥80 in 72% of patients. IDH status was available in 40% of patients and was predominantly wild-type. Standard radiotherapy to 60 Gy in 30 fractions was delivered in 70% of patients, whereas 30% received hypofractionated or alternative regimens. During follow-up, 40 deaths and 45 PFS events were observed. Median OS was 14.0 months, with estimated OS rates of 79.9%, 52.3%, 41.2%, and 25.3% at 6, 12, 18, and 24 months, respectively. Median PFS was 9.7 months, with estimated PFS rates of 69.9%, 38.2%, 25.3%, and 16.1% at 6, 12, 18, and 24 months, respectively. In exploratory multivariable analyses, increasing age at diagnosis appeared to correlate with worse OS, while multifocal disease and larger lesion diameter on MRI appeared to correlate with poorer outcomes.
Conclusion: This retrospective real-world cohort demonstrated survival outcomes consistent with contemporary glioblastoma series. Increasing age, multifocal disease, and larger tumor burden appeared to be associated with poorer outcomes. Given the retrospective design, limited sample size, and incomplete molecular profiling, these findings should be considered hypothesis-generating rather than definitive prognostic evidence.
Keywords: Glioblastoma; Central Nervous System Tumors; Radiotherapy; Survival Outcomes; Prognostic Factors.
