gms | German Medical Science

Objective: Ependymoma are the third most common brain tumor in pediatrics. The majority of tumors (60-70%) arise in the posterior fossa with a higher fraction of grade III tumors. Despite similar histopathological features the prognosis is strikingly heterogeneous ranging from early recurrences, multiple tumor operations and distant metastasis to completely progression-free clinical courses. In this study, we sought to assess the clinical course of supra- and infratentorial tumors and define factors associated with outcome parameters, as recurrence or metastasis.

Methods: Thirty-seven children with the diagnosis of Ependymoma were included between 1990 and 2016. Demographic parameters, treatment modalities (resection, chemo-, radiotherapy) and the clinical course (no. of operations, recurrences, distant metastasis) were assessed retrospectively using medical records. Fisher’s exact test and the two-sided t-test were applied for statistical analysis.

Results: In our patient cohort, tumor location was infratentorial in 73% of patients (N =27). In 64.9% of cases (N=24) an anaplastic ependymoma (grade III) was diagnosed. In 52.9 % of patients (N=18) a recurrence was diagnosed and 23.5% of patients had spinal or distant metastasis. The mortality was 36.7% until the time of data collection. Children with grade III tumors were significantly younger than children with grade II tumors (p=0.006). In our cohort, supra- and infratentorial tumors showed no differences concerning recurrence, death, no. of operations and spinal or distant metastasis. But for supratentorial tumors, there was an association between tumor grade and recurrence (p=0.012) and also between tumor grade and no. of operations (p=0.033). All children with supratentorial tumors grade III (N=6) experienced recurrence. Infratentorial tumors showed no association between tumor grade and recurrence. Time to progression was significantly shorter for infratentorial tumors compared to supratentorial tumors, independently of tumor grade (p=0.01). We did not detect an association between the extent of resection and recurrence or metastasis (p>0,5).

Conclusion: Supra- and infratentorial ependymoma show distinct clinical courses in pediatric patients. Especially for supratentorial tumors, histological tumor grading is associated with clinical outcome factors. In infratentorial tumors, factors other than tumor grading seem to influence clinical outcome. Further studies are necessary to assess prognostic factors, particularly in infratentorial tumors to stratify the risk profile.