PATH-93. Aggressive Course of IDH-Wildtype Glioblastoma in Young Adults: Clinical Outcomes May Be Worse Than in the Elderly

Glioblastoma (GBM), IDH-wildtype, WHO grade 4 of the Central Nervous System (CNS), classically affects older patients (median age of 65 years) with a poor prognosis. Although younger age is generally associated with a better prognosis in gliomas (especially IDH-mutant), IDH-wildtype GBM also exhibits an aggressive course in young adults. Diagnostic confirmation via DNA Methylation Profiling (WHO 2021) is crucial. We present a case series of young adults with IDH-wildtype GBM, evaluating their clinical outcomes.We conducted a retrospective analysis of four patients with GBM confirmed by Methylation Profiling. Clinical, radiological, histopathological, and molecular data were collected. The median age at diagnosis was 39.5 years (range 34–51). Despite the young age, disease progression was aggressive. The estimated median overall survival for the cohort was approximately 16 months. For the three patients who died, the median age at death was 38 years (range 35–45 years). This survival outcome e as consistent with published data (14.6 months) and slightly better than in elderly patients (9.3 months), underscores the aggressiveness of the disease even in this younger age group. Progression patterns were marked by worse clinical outcomes, including local recurrence, multifocal relapse, rapid progression, lower response rates, and leptomeningeal spread. IDH-wildtype GBM in young adults appears to present a distinct course, with increased multifocal progression and leptomeningeal dissemination. This series reinforces the need for better molecular and risk stratification in the diagnosis of IDH-wildtype GBM, especially in younger patients.