Objectives: To assess the long-term outcomes and objective response (OR) to preradiation chemotherapy and radiation in adult high-risk medulloblastoma.
Materials and methods: In this prospective phase II trial, adults with high-risk medulloblastoma were treated with 3 cycles of preradiation cisplatin, etoposide, cyclophosphamide, and vincristine followed by craniospinal radiation (CSI). OR, progression-free survival (PFS), overall survival (OS), and toxicities were assessed.
Results: Eleven patients were enrolled over a 6-year period. Six (55%) had subarachnoid metastases. Two (18%) had an OR to preradiation chemotherapy. Two (18%) progressed while on chemotherapy. Completion of CSI was not compromised. The OR rate after chemotherapy and radiation was 45% (5/11). Nonevaluable patients at both time-points weakened the response data conclusions. Median PFS was 43.8 months. Five-year PFS was 27%. Five-year OS was 55%. Nonmetastatic (M0) and metastatic (M+) patients had similar outcomes.
Conclusions: The OR to this preradiation chemotherapy regimen is lower than anticipated from the adult and pediatric literature raising a question about comparative efficacy of chemotherapy in different age groups. The OS achieved is similar to retrospective adult series, but worse than pediatric outcomes. Although this regimen can be administered without compromising delivery of CSI, our results do not provide support for the use of this neoadjuvant chemotherapy for adult medulloblastoma.