EPID-17. A SINGLE CENTER RESTROSPECTIVE REVIEW OF RECURRENT OR TREATMENT REFRACTORY PEDIATRIC MEDULLOBLASTOMA

The outcome of pediatric refractory or relapsed brain tumours remains a concern for treating neurooncology teams with the most effective salvage therapy yet to be established. Upfront therapy for primary medulloblastoma (MB) is dependent on age, post-operative residual and evidence of metastasis at diagnosis. Children diagnosed with aggressive subtypes of MB that are refractory to upfront therapy or recur either in the resection cavity or as distant metastases have a very poor prognosis. Reports of phase I and II studies for these children exist, but these therapies bear significant treatment related morbidity and mortality. A retrospective review of children diagnosed with a pediatric MB from 2002–2017 from the McMaster Pediatric Brain Tumour Study Group (PBTSG) captured a number of pediatric recurrent MB. Subsequently the treatments received and outcomes were identified. Over the 15-year period, 30 children with a histological diagnosis of MB were treated. Ten children were recurrent or treatment refractory MB. The 5-year outcome survival (OS) for this group of patients as compared to no recurrence was 20% and 90% respectively. The mean follow-up for survivors of recurrent MB however was 3.2 years. In 4 of 10 recurrent MB, the disease had significantly progressed and palliated. For the remaining children, therapy offered included cyberknife, imatinib, etoposide, vinblastine, temsirolimus, imatinib, tipifarnib, temozolamide, and irinotecan either in isolation or in varying combinations. Congruent to the literature, recurrent MB in our single center cohort carried a poor prognosis despite administration of salvage therapy.