Retrospective analysis of treatment outcome of pediatric ependymomas in Korea: analysis of Korean multi-institutional data

Current and Emerging Methods of Management of Ependymoma

PURPOSE OF REVIEW

This review discusses the evidence base behind current and emerging strategies of management of intracranial and spinal ependymomas in children, with a particular focus on aspects of surgical techniques, challenges and complications.

RECENT FINDINGS

The cornerstone of management remains maximal safe resective surgery, which has repeatedly been shown to correlate with improved survival. This is followed by focal conformal radiotherapy, although good results using proton beam therapy, with the potential for diminished side effects, are emerging. The role of chemotherapy remains largely unproven for paediatric ependymoma. Despite optimal management strategies, many children with ependymoma suffer from tumour recurrence. The standard of care for paediatric ependymoma comprises surgery and radiotherapy. Results of ongoing clinical trials will help shape its management in order to leverage our increasingly sophisticated understanding of the genetic drivers behind these tumours into survival benefit for this challenging group of patients.

Tumor-infiltrating immune cell subpopulations and programmed death ligand 1 (PD-L1) expression associated with clinicopathological and prognostic parameters in ependymoma

Ependymomas are biologically and clinically heterogeneous tumors of the central nervous system that have variable clinical outcomes. The status of the tumor immune microenvironment in ependymoma remains unclear. Immune cell subsets and programmed death ligand 1 (PD-L1) expression were measured in 178 classical ependymoma cases by immunohistochemistry using monoclonal antibodies that recognized tumor-infiltrating lymphocyte subsets (TILs; CD3, CD4, CD8, FOXP3, and CD20), tumor-associated macrophages (TAMs; CD68, CD163, AIF1), indoleamine 2,3-dioxygenase (IDO)+ cells and PD-L1-expressing tumor cells. Increases in CD3+ and CD8+ cell numbers were associated with a prolonged PFS. In contrast, increased numbers of FOXP3+ and CD68+ cells and a ratio of CD163/AIF1+ cells were significantly associated with a shorter PFS. An increase in the IDO+ cell number was associated with a significantly longer PFS. To consider the quantities of TILs, TAMs, and IDO+ cells together, the cases were clustered into 2 immune cell subgroups using a k-means clustering analysis. Immune cell subgroup A, which was defined by high CD3+, low CD68+ and high IDO+ cell counts, predicted a favorable PFS compared to subgroup B by univariate and multivariate analyses. We found six ependymoma cases expressing PD-L1. All these cases were supratentorial ependymoma, RELA fusion-positive (ST-RELA). PD-L1 expression showed no prognostic significance. This study showed that the analysis of tumor-infiltrating immune cells could aid in predicting the prognosis of ependymoma patients and in determining therapeutic strategies to target the tumor microenvironment. PD-L1 expression in the ST-RELA subgroup suggests that this marker has a potential added value for future immunotherapy treatments.

Analysis on therapeutic outcomes and prognostic factors of intracranial ependymoma: a report of 49 clinical cases in a single center

Although intracranial ependymoma is relatively rare, it is often associated with great clinical aggressiveness and poor overall survival. There are controversies over factors affecting the prognosis of the disease. The aim of this retrospective study was to evaluate factors that may affect the therapeutic outcome and prognosis of intracranial ependymoma by reviewing the medical records of 49 patients who were surgically treated in our hospital between 2001 and 2014. Univariate and multivariate analyses were performed to identify prognostic variables relative to patient and tumor characteristics, and treatment modalities. All 49 patients (24 men and 25 women; mean age 27.6 years) underwent surgical resection, of whom 14 patients also underwent postoperative radiotherapy. Local recurrence was found in 15 (48.8 %) patients, and 22 (51.2 %) patients died during the follow-up periods. The 5-year recurrence rate was 65 % and the survival rate was 51 %. The results of statistical analysis suggested that preoperative extraventricular drainage and surgical resection extent were prognostic factors related to progression-free survival, and that age, surgical resection extent and histological grade were closely associated with survival. Interestingly, there was a significant correlation between the symptom of hydrocephalus and age (P = 0.010), and patients with a better clinical status (KPS ≥ 80) were significantly associated with a lower WHO grade (P = 0.007). In conclusion, we confirmed that surgical resection extent was the major independent factor affecting both recurrence and survival of patients with intracranial ependymoma, while age and WHO grade were prognostic factors affecting survival but not recurrence.