Background: Ependymomas are central nervous system tumors that significantly impact the quality of life and carry a high mortality rate. Both the disease itself and its treatment cause significant morbidity. At a national level in Peru, there are no reports on clinical characteristics of the disease. Methods: This retrospective study captured patient aged less than 19 years with a diagnosis of ependymoma from 2012 to 2022 at a tertiary center in Lima. Results: 85 patients were included with a median follow-up time was 51.6 months. The 5-year overall survival and progression-free survival were 55.89% (95% CI: 44.28 – 65.99) and 37.71% (95% CI: 26,21-49,16) respectively. The main prognostic factors identified were completed treatment (p=0.019), adjuvant chemotherapy (p=0.048), presence of metastasis (p=0.012), and disease recurrence (p=0.02). Conclusions: The survival of patients with ep...

Background: A high frequency of primary central nervous system (CNS) sarcomas was observed in Peru. This article describes the clinical characteristics, biological characteristics, and outcome of 70 pediatric patients. Methods: Data from 70 pediatric patients with primary CNS sarcomas diagnosed between January 2005 and June 2018 were analyzed. DNA methylation profiling from 28 tumors and gene panel sequencing from 27 tumors were available. Results: The median age of the patients was 6 years (range, 2-17.5 years), and 66 of 70 patients had supratentorial tumors. DNA methylation profiling classified 28 of 28 tumors as primary CNS sarcoma, DICER1 mutant. DICER1 mutations were found in 26 of 27 cases, TP53 mutations were found in 22 of 27 cases, and RAS-pathway gene mutations (NF1, KRAS, and NRAS) were found in 19 of 27 tumors, all of which were somatic (germline control available in 19 case...