Large cell/anaplastic medulloblastoma is associated with poor prognosis-a retrospective analysis at a single institute.

PURPOSE: Medulloblastoma (MB) is the most commonly occurring malignant pediatric brain tumor worldwide. However, a recent study found that the treatment outcomes in those with high-risk disease receiving conventional treatment were suboptimal. This study aimed to assess outcomes and treatment strategies for specific histologic subtypes of pediatric MB.

METHODS: A total of 114 pediatric patients (age < 20 years) diagnosed with MB between March 1998 and August 2011 were retrospectively reviewed; 52 that were treated with surgery followed by adjuvant radiotherapy (RT) and chemotherapy (CHT) were included.

RESULTS: The 5-year overall survival (OS) and relapse-free survival (RFS) rates were 73 and 69%, respectively. Median time to relapse was 17 months with a median survival time of 6 months after relapse. Patients of average risk had a better 5-year OS rate compared with high-risk patients (p = 0.027). The 5-year RFS of high-risk patients was lower compared with average risk (p = 0.038). A greater proportion of patients with large cell/anaplastic (LC/A) MB had recurrence than classic MB with 5-year RFS rate of 34 and 76%, respectively (p = 0.001), and OS rate of 56 and 76%, respectively (p = 0.04).

CONCLUSION: High-risk group and histology of LC/A were the most significant factors associated with worse OS and RFS. Patients with LC/A-MB had higher relapse rates and worse survival than those with classic MB. LC/A-MB carries a high risk for recurrence and should be treated with the more aggressive strategies.