A retrospective analysis of recurrent pediatric ependymoma reveals extremely poor survival ind ineffectiveness of current treatments across central nervous locations and molecular subgroups. Tryggve Lundar MD, PhD1,2, Bernt Johan Due-Tønnessen MD,PhD1Radec Fric MD,PhD1Department of Neurosurgery, Oslo University Hospital1and University of Oslo2Correponding author:Tryggve LundarDepartment of NeurosurgeryOslo University HospitalPostboks 4950 Nydalen, Oslo, NorwayEmail: [email protected] word count: 474Short running title: GTR can improve outcome after relapse of pediatric ependymomaKey words: Pediatric ependymoma, relapse, repeat surgical resection (GTR)Number of tables: 0Number of figures: 0Letter to the EditorPediatr Blood CancerDear Editor,RE: Ritzmann TA, Rogers HA, Paine SML, Storer LCD, Jacques TS, Chapman RJ, Ellison D, Donson AM, Foreman NK, Grundy RG.A retrospective analysis of recurrent pediatric ependymoma reveals extremely poor survival ind ineffectiveness of current treatments across central nervous locations and molecular subgroups.Pediatr Blood Cancer 2020;67:e28426https://doi.org/10.1002/pbc.28426Congratulations to the authors with their detailed analysis of further management and outcome in pediatric patients who experience recurrence within a few years after initial treatment for ependymomas.Initial treatment for posterior fossa ependymomas (PFE) is maximal surgical resection (Gross total resection-GTR; if possible) followed by local radiotherapy or chemotherapy in small children. For supratentorial ependymomas (STE) GTR is also recommended (if possible) with or without postoperative radiotherapy.The management at relapses is, however, without consensus. The authors confirm the grave prognosis for these children. In the beginning of the discussion they state: Although primary surgery and irradiation reduced relapse risk variability in different intracranial locations, once a patient recurred these interventions gave, at best, short-term benefits, confirming the need for better therapies.This of course true – better therapies are urgently needed. They point to the lack of consensus regarding treatment at relapse, but recent guidelines have recommended the use of reirradiation and further surgery. In the conclusion they underline that recurrent pediatric ependymoma is highly aggressive with extremely poor outcome.This negative statement, is to some extent, in conflict with the results given under 3.5.2. At relapse: GTR at first relapse was associated with sustained improved EFS (25% vs 0% 10-year survival).This statement is in accord with Vinchon et al1 : Total resection is the only curative treatment for RIE (recurrent intracranial ependymoma) and is often possible, especially when the initial resection was total.How often GTR is within reach at local relapes may be a difficult matter. We have, however, observed several patients who underwent GTR after recurrence, and are tumor-free today after many years of further follow-up(up to 27 years) without any additional treatment2. We recognize that these patients are few compared to the majority of pediatric ependymoma patients who do not grow-up to be well functioning adults. It is, however, important for these small patients and their caretakers to have a hope for cure even after relapse. The role of GTR if possible may be under-communicated.Kind regardsTryggve LundarBernt Johan Due-TønnessenRadek Fric