Peer-reviewed article
EPEN-04. Refinement of molecular and clinical characteristics in a cohort of 1,801 ependymomas
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Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This is a molecular and clinical study of ependymomas, a type of brain tumor. The research analyzed DNA methylation profiles from 1,801 tumor samples to refine the classification of ependymoma subtypes and their clinical outcomes. While the study includes pediatric patients, it is a basic cancer research study focused on tumor biology and molecular characteristics rather than child well-being interventions or health outcomes in populations.
Key points
- Study analyzed DNA methylation profiles from 1,801 ependymomas to refine ten known molecular types
- EPN-PFA tumors occurred in children in over 98% of cases and showed 10-year overall survival of 56%
- Chromosome 1q gains and 6q losses in EPN-PFA were markers for worse survival
- Combined loss of CDKN2A/B in supratentorial EPN-RELA indicated worse survival (p=0.0004)
- Machine learning algorithms are being developed to predict survival and treatment response
Limitations
This is a descriptive tumor classification and prognostication study, not an evaluation of interventions to improve child health or well-being. It cannot inform us about the effectiveness of treatments or health programs for children.
Abstract
Abstract DNA methylation profiling led to the definition of ten molecular types of ependymomas with distinct biological and clinical features. The largest published reference cohort consists of 500 ependymomas encompassing nine molecular types that were known at this point. Our study aimed to confirm and refine molecular and clinical characteristics of ependymoma types and subtypes based on a considerably larger, well-annotated cohort of ependymal tumors. Here, we analyzed previously published and newly generated DNA methylation profiles, generated on the Illumina 450k and EPIC arrays, from a total of n=1,801 ependymomas. We looked at both global DNA methylation as well as inferred copy number profiles and correlated these data with clinical parameters. Patients with EPN-PFA, EPN-RELA, and EPN-MYCN tumors showed the worst outcome with 10 year-overall survival rates of 56%, 64%, and a 5 year-overall survival rate of 73%, respectively. EPN-PFA, the most frequent tumor type in our series, occurred in children in >98% of cases, epigenetically split into two major subtypes, and harbored chromosome 1q gains and 6q losses as markers for worse survival (p<0.0001 and p=0.042, respectively). In supratentorial EPN-RELA, a combined loss of CDKN2A/B indicated a worse survival compared to the wildtype (p=0.0004), but the loss of only CDKN2A or CDKN2B did not. Ten out of 169 EPN-RELA were located in the posterior fossa, and Kaplan Meier estimators showed that these tumors relapsed or progressed even earlier than supratentorial cases with a combined loss of CDKN2A/B (p=0.0062). SP-MPE and PF-SE, which are generally regarded as non-aggressive tumors, only had a 10-year progression-free survival of 60% and 63%, respectively, in our series. In ongoing analyses, we are training machine learning algorithms to more accurately predict survival and response to treatments. These methods shall help clinicians make informed decisions regarding treatment options on new patients.