Efficacy and safety of multimodality therapy stratified by resection rate and molecular markers in children and adolescents with ependymoma: JCCG EPN23 protocol.

BACKGROUND

Ependymomas are rare pediatric brain tumors characterized by clinical and molecular heterogeneity. The JCCG EPN23 study is a nationwide prospective trial in Japan designed to evaluate outcomes of risk-adapted therapy stratified by tumor location, extent of resection, and molecular classification.

METHODS

Patients younger than 30 years with pathologically confirmed ependymoma are enrolled and assigned to one of three treatment strata. Stratum 1 evaluates whether omission of radiation therapy for patients with gross total resection of supratentorial or non-PFA infratentorial tumors. Stratum 2 administers radiation therapy followed by maintenance oral etoposide for patients with minimal residual tumors or PFA subtype. Stratum 3 provides neoadjuvant chemotherapy to facilitate total resection of residual tumors. Patients younger than 1 year and those with metastatic or extracranial disease are assigned to an observational cohort, in which no specific treatment is mandated by study protocol. Central surgical and pathological review, along with molecular and DNA methylation profiling, are conducted to improve diagnostic precision and prognostic stratification.

RESULTS

The study prospectively evaluates the feasibility and efficacy of radiation-sparing strategies in selected patient groups and other risk-adapted treatment approaches. Outcomes including survival, disease control, and treatment-related morbidity will be analyzed according to each risk group.

CONCLUSIONS

JCCG EPN23 aims to optimize therapeutic strategies for pediatric ependymoma by integrating molecular classification with risk-adapted treatment. The results are expected to inform future treatment protocols and improve survival while minimizing long-term morbidity.