P.044 Salvage therapy in recurrent pediatric medulloblastoma: A single centre experience

Background: Children diagnosed with medulloblastoma (MB) that are refractory to upfront therapy or experience recurrence have very poor prognoses. Reports of phase I and II studies for these children exist, but bear significant treatment related morbidity and mortality. Methods: A retrospective review of children diagnosed with a pediatric MB from 2002-2015 from the McMaster Pediatric Brain Tumour Study Group (PBTSG) captured a number of pediatric recurrent MB. Results: Over the 13-year period, 31 children with a histological diagnosis of MB were treated. At two years, 21 (67.7%) of 31 patients were free of recurrence and 25 (80.6%) survived. Thirteen children had recurrent or treatment refractory MB. mean time to recurrence was 14.6 months. The mean follow-up for survivors of recurrent MB was 4.0 years. In 3 recurrent MB, the disease had significantly progressed and the patients palliated. For the remaining children, therapy offered included surgery, radiation, and chemotherapy agents either in isolation or in varying combinations. Conclusions: Recurrent MB in our cohort carried a poor prognosis despite administration of salvage therapy. Though there is standardization of the upfront treatment exists, we observed great heterogeneity in the treatment of our 13 patients experiencing recurrence. A greater understanding of the biology of recurrent MB has the potential to guide salvage therapy.