Impact of Molecular Subgroups on Prognosis and Survival Outcomes in Posterior Fossa Ependymomas: A Retrospective Study of 412 Cases

Neurosurgery. 2024 Sep 1;95(3):651-659. doi: 10.1227/neu.0000000000002923. Epub 2024 Mar 26.

Abstract

Background and objectives: Posterior fossa ependymomas (PFEs) are rare brain tumors classified as PF-EPN-A (PFA) and PF-EPN-B (PFB) subgroups. The study aimed to evaluate the prognosis and survival outcomes in PFEs, with a focus on the impact of molecular subgroups.

Methods: A retrospective study was conducted on 412 patients with PFEs. Kaplan-Meier survival analyses were conducted to evaluate the overall survival (OS) and progression-free survival. Cox regression analyses were conducted to assess the prognostic factors. A nomogram was developed to predict the OS rates of PFEs.

Results: The study revealed significant differences between PFA and PFB in patient and tumor characteristics. PFAs were associated with poorer OS (hazard ratios [HR] 3.252, 95% CI 1.777-5.950, P < .001) and progression-free survival (HR 4.144, 95% CI 2.869-5.985, P < .001). World Health Organization grade 3 was associated with poorer OS (HR 2.389, 95% CI 1.236-4.617, P = .010). As for treatment patterns, gross total resection followed by radiotherapy or the combination of radiotherapy and chemotherapy yielded the most favorable OS for PFA ( P = .025 for both), whereas gross total resection followed by radiotherapy rather than observation showed improved OS for PFB ( P = .046). The nomogram demonstrated a high degree of accuracy and discrimination capacity for the prediction of OS rates for up to 10 years. In addition, 6 cases of PFA (3.51%) with H3K27M mutations were identified.

Conclusion: PFAs demonstrate worse prognosis and survival outcomes compared with PFBs. Both PFAs and PFBs necessitate maximal resection followed by intensive adjuvant therapies in long-term effects.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Ependymoma* / diagnosis
  • Ependymoma* / genetics
  • Ependymoma* / mortality
  • Ependymoma* / pathology
  • Ependymoma* / therapy
  • Female
  • Humans
  • Infant
  • Infratentorial Neoplasms* / genetics
  • Infratentorial Neoplasms* / mortality
  • Infratentorial Neoplasms* / therapy
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Nomograms
  • Prognosis
  • Retrospective Studies
  • Young Adult