P07.03 * RECURRENT MEDULLOBLASTOMA AND CNS PNET IN ADULTS - RESULTS OF VIP CHEMOTHERAPY

Abstract

INTRODUCTION: Medulloblastoma and central nervous system (CNS) primitive neuroectodermal tumor (PNET) are rare embryonal brain tumors in adults. Surgery and radiotherapy are an important part of the initial treatment, however, the role of (neo)adjuvant chemotherapy or chemotherapy at relapse is still unclear. In our center, etoposide/ifosfamide/cisplatin (VIP) chemotherapy is the standard of care for patients with a first relapse of medulloblastoma or CNS PNET. We reviewed the outcome in a consecutive series of patients treated with VIP chemotherapy at first relapse in our center between 2004 and 2012. MATERIALS AND METHODS: Patients were treated with 3 weekly cycles consisting of etoposide 75 mg/m2 d1-5, ifosfamide 1200 mg/m2 d1-5, and cisplatin 20 mg/m2 d1-5, followed by pegfilgrastim 6 mg s.c. d6, for a maximum of 4 cycles. We assessed toxicity using the CTCAE version 4 criteria (CTC), response, progression-free survival and overall survival measured from the day of start of chemotherapy. RESULTS: Twelve adult patients diagnosed with medulloblastoma (n = 6) and CNS PNETs (n = 6) were treated. The median age at first diagnosis was 34.6 years. After resection of the tumor eleven patients received craniospinal radiotherapy with a boost on the primary tumor site(n = 11); One patient received craniospinal radiation only because of adverse side effects. One patient had been treated with (neo)adjuvant chemotherapy (vincristine/carboplatin/cyclophosphamide) at the time of first diagnosis. The median time from diagnosis until time of first relapse was 18.5 months. At start of VIP, the median performance score was WHO 1. Nine patients were treated with the maximum number of 4 cycles VIP, in 3 patients VIP was stopped prematurely because of progressive disease (PD). Grade 3-4 CTC adverse effects were described in 8 patients: thrombocytopenia (n = 6); anemia (n = 6); leukopenia (n = 4); neutropenia (n = 4), and ototoxicity (n = 2). Three patients showed a partial response (PR) after VIP, 5 patients showed stable disease (SD) and 4 patients PD. After treatment with VIP chemotherapy median progression-free survival (PFS) was 5.3 months (medulloblastoma 10.5 months; CNS PNET 4.3 months) and median overall survival (OS) was 7.5 months (medulloblastoma 27 months; CNS PNET 5.3 months). These differences are not significant. Five of all patients (42%) were still alive one year after receiving VIP therapy. CONCLUSION: The results of this study underline the poor prognosis of adult patients with recurrent medulloblastoma or CNS PNETs. VIP chemotherapy accomplishes a disease stabilization or response in 75% of the patients but of short duration. There is a trend showing a better response to VIP therapy in medulloblastoma patients compared to CNS PNETs.