Treatment of adult medulloblastoma: a single-center experience

Aim Medulloblastoma is an aggressive embryonal neuroepithelial tumor of the posterior fossa. It accounts for approximately 20% of pediatric brain tumors but has a low annual incidence in adults, comprising less than 1% of adult intracranial neoplasms. This study aimed to present our treatment experience with adult medulloblastoma. Material and methods We retrospectively analyzed the clinical, demographic, and pathological features, treatment modalities, toxicity profiles, and survival outcomes of 17 adult medulloblastoma patients diagnosed at our center between 2005 and 2021. Results The median patient age was 33.8 years (range, 18–54 years). The most common presenting symptoms were dizziness (70.6%), headache (58.8%), nausea/vomiting (35.3%), and visual disturbances (29.4%). The median interval from symptom onset to hospital admission was 30 days (range, 5–365 days). Anaplastic histology was documented in one patient; however, incomplete historical metastatic staging precluded reliable clinical risk stratification across the cohort. Sixteen patients received craniospinal irradiation, and 12 patients received adjuvant chemotherapy. The median interval between surgery and radiotherapy initiation was 43.5 days (range, 21–129 days). Sixteen patients initiated CSI, with a prescribed dose of 36 Gy in 20 fractions. The estimated 5-year PFS and OS rates were 61.1% and 66.6%, respectively, while the corresponding 10-year rates were 50.9% and 55.5%. In exploratory, unadjusted analyses, adjuvant chemotherapy was associated with longer PFS (log-rank p=0.008), but not OS (p=0.075). However, when chemotherapy initiation was modeled as a time-dependent exposure, neither association was statistically significant (PFS: HR 0.26, 95% CI 0.04–1.53, p=0.137; OS: HR 0.61, 95% CI 0.07–5.39, p=0.654). The most common grade ≥3 hematologic toxicities of adjuvant chemotherapy were neutropenia (50%) and thrombocytopenia (41.7%). Conclusion Long-term survival outcomes in this single-center adult medulloblastoma cohort were comparable with those reported in previous series. In time-dependent analyses, associations between adjuvant chemotherapy and PFS or OS did not reach statistical significance. However, this finding should be interpreted cautiously because of the small sample size, retrospective design, treatment heterogeneity, and potential selection bias.