Long-term outcomes and role of chemotherapy in adults with newly diagnosed medulloblastoma.

Objective: To assess the survival and role of adjuvant chemotherapy in adult medulloblastoma.

Methods: We reviewed outcomes of 66 patients (aged 18 y or more; median age, 33 y) with medulloblastoma. Forty-four (67%) patients had M0 disease, 9 had M1-M4, and 13 had MX. Thirty-one patients each for whom risk stratification was available were classified as high risk or standard risk. Fifty-six patients had histologic results: classic histology was the most common (n=46 [84%]), followed by desmoplastic (n=9), and large cell/anaplastic (n=1). Overall survival (OS) and progression-free survival (PFS) were estimated with Kaplan-Meier curves and log-rank tests. Cox regression analysis was used to compare recurrences.

Results: Median follow-up was 6.7 years. The estimated 5-year OS and PFS were 74% and 59%, respectively. High-risk versus standard-risk classification was associated with worse OS (61% vs. 86%; P=0.03) and recurrence (hazard ratio, 2.56; P=0.05) and a trend for worse PFS (49% vs. 69%; P=0.13). Gross total resection was associated with improved OS (P=0.03) and a trend toward improved PFS (P=0.09). No chemotherapy benefit could be demonstrated for the group as a whole. For high-risk patients with classic histology (n=25), chemotherapy was associated with a trend for improvement in 5-year PFS from 36% to 71% (P=0.10) and in 5-year OS from 49% to 100% (P=0.08).

Conclusions: In adult patients with medulloblastoma, the extent of resection and risk classification predicts the outcome. These results suggest a chemotherapy benefit for high-risk patients with classic histology.