10244-CS-24 Current status and challenges of adult medulloblastoma treatment

Abstract Background/Method Medulloblastoma is major childhood brain tumor which is rare cancer with an annual incidence of 5 cases per 1 million children. According to the 2016 national cancer registry data, the annual incidence rate in Japan is 93 cases. In particular, adult cases are rare, accounting for 10% of all medulloblastoma cases. In this study, we conducted a clinical study of adult medulloblastoma cases diagnosed and treated at our hospital. Result Eight cases were analyzed. The mean age was 33. 3(22-48) years, and the median was 33 years. Three (37.5%) were male and five (62.5%) were female. Tumor location was in the vermis in four (50%) cases and the cerebellar hemisphere in four (50%) cases. GTR was achieved in all cases, and none had leptomeningeal dissemination. All cases were in the standard-risk group. Radiation therapy consisted of local irradiation at 32.4 Gy + whole-brain/whole-spin irradiation at 23.4 Gy in six (75%) cases, and the other two cases received a similar dose. Chemotherapy consisted of the Packer protocol, the standard treatment for children, in seven (87.5%) cases, and carboplatin plus etoposide in one case. Adverse events such as bone marrow suppression due to cisplatin and cyclophosphamide were inevitable, but the protocol could be implemented without delay by timely administration of long-acting G-CSF preparations. Dose reduction was performed in 3 cases (37.5%) due to hearing loss of Grade 2 or higher caused by cisplatin, and in 6 cases (75%) due to finger numbness caused by vincristine. One case (12.5%) showed recurrence during follow-up and underwent stereotactic radiotherapy. Discussion/Conclusion Chemotherapy for adults have stronger side effects than for children, but of the cases analyzed, seven patients completed eight courses of the Packer protocol, although the drug dose was reduced along the way, and all are still alive to date. It is important to complete chemotherapy while appropriately managing side effects.