Adult medulloblastoma: Long-term follow-up analysis of a single-center cohort.

Abstract

e14104 Background: Medulloblastoma (MB) is a malignant embryonal neoplasm of the central nervous system (CNS) that is more common in children and rare in adults—a setting in which there is limited clinical evidence to guide treatment and prognostication. Report of an adult MB cohort treated exclusively at our institution focusing on therapies performed and oncological outcomes in the long term. Methods: This is an observational retrospective cohort study including patients aged 17 years or older with a histological diagnosis of MB. Survival curves were estimated using the Kaplan–Meier method and compared using the log-rank test. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models. Variables with clinical relevance were evaluated in univariable analyses to explore their association with OS and PFS. Level of significance was defined as a two-sided (alpha = 0.05). All statistical analyses were performed using R software (survival package). Results: From 2008 to 2025, 72 patients were included in the analysis. Median time of follow-up is 169,57 months. Forty-nine male and 23 female; median age at diagnosis 28 years. All patients underwent surgery; gross total resection in 52 patients (73,2%). Histological subtypes were nodular/desmoplastic found in 31 patients (43.1%); 55 patients (82,1%) were staged as Chang score M0. Sixty-one patients received any adjuvant therapy (84,7%), radiotherapy with concomitant vincristine in 35 patients (58.3%) and radiotherapy alone in 22 patients (37.2%). Forty-one patients (67.2%) received adjuvant chemotherapy using three-drug regimens. Recurrence was diagnosed in 27 patients (37,5%), with a median time from diagnosis to recurrence of 41 months, and 19 patients received salvage therapy. Median overall survival was 157 months for the whole cohort (95% CI: 98,9 – NA), and median progression-free survival 96 months (95% CI: 63 – NA). Variables associated with worse prognosis included absence of adjuvant therapy (HR 12.97; 95% CI: 5.44–30.91; p:7x10-9) and recurrence (HR 7.59; 95% CI: 3.29–17,54; p: 2×10−6). Variables correlated with improved OS included: concomitant vincristine and radiotherapy (HR 0,4; 95% CI: 0,16 - 1; p: 0,05), and use of adjuvant chemotherapy (HR 0,3; 95% CI: 0,14-0,63; p: 0,001). Gross total resection (GTR) was not associated with improved OS (HR 0.76; 95% CI: 0.34–1.7; p: 0,5). Conclusions: This work represents the largest single-center cohort reported of adult medulloblastoma. This study highlights the importance of employment of adjuvant therapy following initial surgery and underlines the favorable prognosis in the adult MB patients.