Infant Ependymoma in a 10-Year AIEOP (Associazione Italiana Ematologia Oncologia Pediatrica) Experience With Omitted or Deferred Radiotherapy

The Positive Impact of a Chemotherapeutic Approach on Relapse Ependymoma or WHO Grade III Anaplastic Ependymoma: Report of a Rare Case

Children with recurrent ependymoma have a poor prognosis. Reirradiation has been proposed as an effective treatment for relapsed ependymoma. In this report, we present the case of a 14-year-old male child with a World Health Organization (WHO) grade III relapse ependymoma, emphasizing the imaging feature that helps differentiate the relapse ependymoma, which is a rarer condition in children. Being able to determine this tumor by its imaging appearance is important to risk stratify patient management decisions. The survival rate of ependymoma is usually five years, but in this case, we present a 14-year-old male child alive with reirradiation and chemotherapy management. The prognosis of the patient after undergoing treatment was good.

A systematic review and meta-analysis of outcomes in pediatric, recurrent ependymoma

PURPOSE

The purpose of this study was to determine outcomes in recurrent pediatric ependymoma.

METHODS

We performed a systematic review of PubMed, Embase, Web of Science and the Cochrane Library for studies reporting on survival outcomes for pediatric patients with recurrent ependymoma. We then performed a meta-analysis of all eligible results. Survival outcomes were identified across location of recurrence, therapy at recurrence, and age at recurrence.

RESULTS

Eleven studies met final inclusion criteria. Pooled median progression free survival (PFS) from date of first recurrence was 6.7 months (95% confidence interval [95% CI] 4.7-8.8). Pooled median overall survival (OS) from date of first recurrence was 11.2 months (95% CI 6.4-16.0). Participants with supratentorial recurrences demonstrated a shorter OS of 8.3 months (95% CI 3.2-13.3) compared to 20.1 months (95% CI 8.4-31.7) for those with infratentorial recurrence. Patients who underwent surgery at recurrence had a median OS of 24.2 months (95% CI 14.2-34.1) compared to 29.2 months (95% CI 17.4-41.1) in those who received radiation compared to 19.3 months (95% CI 10.3-28.3) in those who received chemotherapy. Patients younger than age 3 years at time of recurrence demonstrated a median OS of 31.0 months (95% CI - 25.3-87.3) compared to 17.5 months (95% CI 9.9-25.2) for those that recurred beyond 3 years of age.

CONCLUSIONS

Our findings illustrate that children with recurrent ependymoma suffer from poor outcomes; however, these outcomes range widely depending on patient, tumor, and treatment characteristics. New therapies and treatment strategies are needed to improve outcomes in this group.

A role for ABCB1 in prognosis, invasion and drug resistance in ependymoma

Three of the hallmarks of poor prognosis in paediatric ependymoma are drug resistance, local invasion and recurrence. We hypothesised that these hallmarks were due to the presence of a sub-population of cancer stem cells expressing the multi-drug efflux transporter ABCB1. ABCB1 gene expression was observed in 4 out of 5 paediatric ependymoma cell lines and increased in stem cell enriched neurospheres. Functional inhibition of ABCB1 using vardenafil or verapamil significantly (p ≤ 0.05–0.001) potentiated the response to three chemotherapeutic drugs (vincristine, etoposide and methotrexate). Both inhibitors were also able to significantly reduce migration (p ≤ 0.001) and invasion (p ≤ 0.001). We demonstrate that ABCB1 positive patients from an infant chemotherapy-led trial (CNS9204) had a shorter mean event free survival (EFS) (2.7 versus 8.6 years; p = 0.007 log-rank analysis) and overall survival (OS) (5.4 versus 12 years; p = 0.009 log-rank analysis). ABCB1 positivity also correlated with reduced event free survival in patients with incompletely resected tumours who received chemotherapy across CNS9204 and CNS9904 (a radiotherapy-led SIOP 1999-04 trial cohort; p = 0.03). ABCB1 is a predictive marker of chemotherapy response in ependymoma patients and vardenafil, currently used to treat paediatric pulmonary hypertension in children, could be repurposed to reduce chemoresistance, migration and invasion in paediatric ependymoma patients at non-toxic concentrations.

The European Society of Paediatric Oncology Ependymoma-II program Core-Plus model: Development and initial implementation of a cognitive test protocol for an international brain tumour trial

It is increasingly accepted that survival alone is an inadequate measure of the success of childhood brain tumour treatments. Consequently, there is growing emphasis on capturing quality of survival. Ependymomas are the third most frequently occurring brain tumours in childhood and present significant clinical challenges. European Society of Paediatric Oncology Ependymoma II is a comprehensive international program aiming to evaluate outcomes under different treatment regimens and improve diagnostic accuracy. Importantly, there has been agreement to lower the age at which children with posterior fossa ependymoma undergo focal irradiation from three years to either eighteen months or one year of age. Hitherto radiotherapy in Europe had been reserved for children over three years due to concerns over adverse cognitive outcomes following irradiation of the developing brain. There is therefore a duty of care to include longitudinal cognitive follow-up and this has been agreed as an essential trial outcome. Discussions between representatives of 18 participating European countries over 10 years have yielded European consensus for an internationally accepted test battery for follow-up of childhood ependymoma survivors. The 'Core-Plus' model incorporates a two-tier approach to assessment by specifying core tests to establish a minimum dataset where resources are limited, whilst maintaining scope for comprehensive assessment where feasible. The challenges leading to the development of the Core-Plus model are presented alongside learning from the initial stages of the trial. We propose that this model could provide a solution for future international trials addressing both childhood brain tumours and other conditions associated with cognitive morbidity.

Newly Diagnosed Metastatic Intracranial Ependymoma in Children: Frequency, Molecular Characteristics, Treatment, and Outcome in the Prospective HIT Series

BACKGROUND

Data on frequency, clinical presentation, and outcome of primary metastatic intracranial ependymoma in children are scarce.

PATIENTS AND METHODS

Prospective data on patients younger than 21 years with metastatic intracranial ependymoma at first diagnosis, registered from 2001 to 2014 in the HIT-2000 trial and the HIT-2000 Interim Registry, were analyzed.

RESULTS

Of 453 registered patients with intracranial ependymoma and central neuropathology review, initial staging included spinal magnetic resonance imaging in all patients and lumbar cerebrospinal fluid (CSF) analysis in 402 patients. Ten patients (2.2%) had metastatic disease, including three with microscopic CSF positivity only (M1 metastasis stage, 0.7% of patients with CSF staging). Location of the primary tumor was supratentorial in four patients (all supratentorial RELA-fused ependymoma [ST-EPN-RELA]) and within the posterior fossa in five patients (posterior fossa ependymoma type A [PF-EPN-A], n = 4; posterior fossa ependymoma not further classifiable, n = 1), and multifocal in one patient.All four patients with ST-EPN-RELA were alive in first or second complete remission (CR) 7.5-12.3 years after diagnosis. All four patients with macroscopic metastases of posterior fossa or multifocal ependymoma died. Three patients with initial M1 stage (ST-EPN-RELA, n = 1; PF-EPN-A, n = 2) received chemotherapy and local irradiation and were alive in second or third CR 3.0-9.7 years after diagnosis. Progression-free and overall survival of the entire cohort at 5 years was 13% (±6%), and 58% (±16%), respectively.

CONCLUSION

Primary metastatic disease is rare in children with intracranial ependymoma. Prognosis may depend on molecular subgroup and extent of dissemination, and relevance of CSF analysis for initial staging remains to be clarified.

IMPLICATIONS FOR PRACTICE

Childhood ependymoma presenting with metastasis at first diagnosis is very rare with a frequency of 2.4% in this population-based, well-characterized cohort. Detection of microscopic metastases in the cerebrospinal fluid was extremely rare, and impact on prognosis and respective treatment decision on irradiation field remains unclear. Initial metastatic presentation occurs in both supratentorial RELA-fused ependymoma and posterior fossa ependymoma. Prognosis may differ according to extent of metastasis and biological subgroup, with poor prognosis in diffusely spread metastatic posterior fossa ependymoma even after combination therapy with both intensive chemotherapy and craniospinal irradiation, which may help to guide individual therapeutic decisions for future patients.

Neurocognitive, academic and functional outcomes in survivors of infant ependymoma (UKCCSG CNS 9204)

PURPOSE

This is the first UK multi-centre case-controlled study with follow-up in excess of 10 years to report the neurocognitive, academic and psychological outcomes of individuals diagnosed with a brain tumour in early childhood. Children enrolled into the UKCCSG CNS 9204 trial, diagnosed with intracranial ependymoma when aged ≤ 36 months old, who received a primary chemotherapy strategy to defer or avoid radiotherapy, were recruited.

METHODS

Outcomes of those who relapsed and subsequently received radiotherapy (n = 13) were compared to those enrolled who did not relapse (n = 16), age-matched controls-diagnosed with solid non-central nervous system (SN-CNS; n = 15) tumours or low-grade posterior fossa pilocytic astrocytoma (PFPA; n = 15), and normative data. Analyses compared nine neurocognitive outcomes as primary measures with quality of survival as secondary measures.

RESULTS

Relapsed ependymoma participants performed significantly worse than their non-relapsed counterparts on measures of Full Scale IQ, Perceptual Reasoning, Word Reading and Numerical Operations. The relapsed ependymoma group performed significantly worse than SN-CNS controls on all primary measures, whereas non-relapsing participants only differed significantly from SN-CNS controls on measures of Processing Speed and General Memory. Relapsed ependymoma participants fared worse than all groups on measures of quality of survival.

CONCLUSIONS

The relapsed irradiated ependymoma group demonstrated the most significantly impaired neurocognitive outcomes at long-term follow-up. Non-relapsing participants demonstrated better outcomes than those who relapsed. Results tentatively suggest avoiding radiotherapy helped preserve neurocognitive and learning outcomes of individuals diagnosed with ependymoma when aged ≤ 36 months old. Prospective neurocognitive surveillance is required. Recommendations for clinical and research practice are provided.

Long-Term Supratentorial Radiologic Effects of Surgery and Local Radiation in Children with Infratentorial Ependymoma

BACKGROUND

Current standard of care for children with infratentorial ependymoma includes maximal safe resection and local radiation of 54-59 Gray. High-dose local radiation has been associated with declines in multiple cognitive domains. The anatomic and physiologic correlates of this cognitive decline remain undefined, and there have been no radiographic studies on the long-term effects of this treatment paradigm.

METHODS

A comprehensive database of pediatric brain tumor patients treated at Stanford Children's from 2004-2016 was queried. Seven patients with posterior fossa ependymoma who were treated with surgery and local radiation alone, who had no evidence of recurrent disease, and had imaging suitable for analysis were identified. Diffusion-weighted magnetic resonance imaging datasets were used to calculate apparent diffusion coefficient maps for each subject, while arterial spin labeling datasets were used to calculate maps of cerebral blood flow. Diffusion-weighted imaging and arterial spin labeling datasets of 52 age-matched healthy children were analyzed in the same fashion to enable group comparisons.

RESULTS

Several statistically significant differences were detected between the 2 groups. Cerebral blood flow was lower in the caudate and pallidum and higher in the nucleus accumbens in the ependymoma cohort compared with controls. Apparent diffusion coefficient was increased in the thalamus and trended toward decreased in the amygdala.

CONCLUSIONS

Surgery and local radiation for posterior fossa ependymoma are associated with supratentorial apparent diffusion coefficient and cerebral blood flow alterations, which may represent an anatomic and physiologic correlate to the previously published decline in neurocognitive outcomes in this population.

Surveillance imaging for high-grade childhood brain tumors: What to do 10 years after completion of treatment?

Brain tumors are the second most common childhood cancer. Treatment protocols for high-grade pediatric brain tumors recommend regular follow-up imaging for up to 10 years. We review maximal time to recurrence and minimal time to radiologically detectable long-term sequelae such as secondary malignancies, vascular complications, and white matter disease. No tumors recurred after the 10-year point, but radiological long-term sequelae grew more common as the treatment completion date receded. We do not recommend regular imaging more than 10 years after treatment has ended, unless there are clinical symptoms.

Patterns of relapse for children with localized intracranial ependymoma

We examined patterns of relapse and prognostic factors in children with intracranial ependymoma. Records of 82 children diagnosed with localized intracranial ependymoma were reviewed. 52% first presented to our institution after relapse. Median age at initial diagnosis was 4 years (range 0-18 years). Gender was 55% male. Initial tumor location was infratentorial in 71% and supratentorial in 29%. Histology was WHO Grade II in 32% and Grade III in 68%. As part of definitive management, 99% had surgery, 70% received RT (26% 2D/3D-conformal RT[CRT], 22% intensity-modulated RT [IMRT], 22% proton), and 37% received chemotherapy. Median follow-up was 4.6 years (range 0.2-32.9). Overall, 74% of patients relapsed (50% local, 17% distant, 7% local + distant) at a median 1.5 (range 0.1-17.5) years. Five-year OS and FFS for patients presenting prior to relapse are 70% (95% confidence interval [CI], 50-83%) and 48% (95% CI 30-64%), respectively. On log-rank, superior overall survival (OS) was demonstrated for gross total resection (p = 0.03). Superior failure-free survival (FFS) was demonstrated for age < 5 years (p = 0.04). No difference in OS or FFS was found between 2D/3D-CRT versus IMRT/proton (p > 0.05). On multivariate analysis, age ≤ 5 was independently associated with a lower risk of death and failure versus older patients (p < 0.05). Contrary to previous reports, young age may not be a poor prognostic factor in patients who can tolerate intensive treatment. Future studies examining patients stratified by clinical and molecular attributes are warranted.

Current Clinical Challenges in Childhood Ependymoma: A Focused Review

Ependymoma is a locally aggressive tumor with metastatic potential that arises in diverse locations throughout the brain and spine in children. Tumor and treatment may result in significant morbidity. Cure remains elusive for many patients owing to diverse biology and resistance to conventional therapy. The implementation of systematic postoperative irradiation in clinical trials during the past 20 years has increased the proportion of patients achieving durable disease control with excellent results, as measured by objective functional outcome measures. Clinical, pathologic, and molecular risk stratification should be used to refine treatment regimens for children with ependymoma to reduce the risk of complications associated with therapy and increase the rate of disease control in the setting of combined modality or more intensive therapy. This review covers standards of care and current clinical trials for children with ependymoma, emphasizing the history and evolution of treatment regimens during the past 20 years and the clinical questions they hoped to address.

Integrating Tenascin-C protein expression and 1q25 copy number status in pediatric intracranial ependymoma prognostication: A new model for risk stratification

PURPOSE

Despite multimodal therapy, prognosis of pediatric intracranial ependymomas remains poor with a 5-year survival rate below 70% and frequent late deaths.

EXPERIMENTAL DESIGN

This multicentric European study evaluated putative prognostic biomarkers. Tenascin-C (TNC) immunohistochemical expression and copy number status of 1q25 were retained for a pooled analysis of 5 independent cohorts. The prognostic value of TNC and 1q25 on the overall survival (OS) was assessed using a Cox model adjusted to age at diagnosis, tumor location, WHO grade, extent of resection, radiotherapy and stratified by cohort. Stratification on a predictor that did not satisfy the proportional hazards assumption was considered. Model performance was evaluated and an internal-external cross validation was performed.

RESULTS

Among complete cases with 5-year median follow-up (n = 470; 131 deaths), TNC and 1q25 gain were significantly associated with age at diagnosis and posterior fossa tumor location. 1q25 status added independent prognostic value for death beyond the classical variables with a hazard ratio (HR) = 2.19 95%CI = [1.29; 3.76] (p = 0.004), while TNC prognostic relation was tumor location-dependent with HR = 2.19 95%CI = [1.29; 3.76] (p = 0.004) in posterior fossa and HR = 0.64 [0.28; 1.48] (p = 0.295) in supratentorial (interaction p value = 0.015). The derived prognostic score identified 3 different robust risk groups. The omission of upfront RT was not associated with OS for good and intermediate prognostic groups while the absence of upfront RT was negatively associated with OS in the poor risk group.

CONCLUSION

Integrated TNC expression and 1q25 status are useful to better stratify patients and to eventually adapt treatment regimens in pediatric intracranial ependymoma.

[Pediatric ependymomas: Current diagnosis and therapy]

Ependymomas represent 10% of pediatric brain tumors. In the recent WHO 2016 classification, pathology is enriched by localization and molecular biology. Whatever the age, total removal by one or several looks when required remains a major prognostic factor. In children, focal radiation remains a standard, while the role of chemotherapy is matter of randomized studies. In infants, front line chemotherapy is the standard. Inclusion in the SIOP ependymoma II protocol is encouraged. In case of relapse, further surgery and radiation are advised, while inclusion in innovative trials including re-irradiation, and phase I-II should be encouraged. A better understanding of underlying mechanisms of ependymoma cell will provide in the close future, the key to use targeted therapies at time of relapse, and very soon as first line therapy for some subgroups of patients.

Re-irradiation of recurrent pediatric ependymoma: modalities and outcomes: a twenty-year survey

Background

Standard treatment for recurrent ependymomas is not defined. Re- irradiation has been proposed but its modalities and results are still to be explored.

Patients and methods

From June 1994 to December 2013, 32 pediatric patients with ependymoma were re-irradiated for local (n = 15) or metastatic (n = 17) relapses. Files were reviewed retrospectively.

Results

Local relapses were treated with hypofractionated focal radiotherapy (hypoFFRT) (n = 8) or focal fractionated radiotherapy (FFRT) (n = 7). Metastatic relapses were treated with hypoFFRT (n = 3), FFRT (n = 3), spinal radiotherapy (n = 4) and craniospinal irradiation (CSI) (n = 7). Median PFS and OS after re-irradiation were 1.2 and 3.5 years respectively with a median follow-up of 2.1 years (0.2–11.4). For local relapses, median PFS was 2.5 years for patients treated with hypoFFRT versus 1.2 years for patients treated with FFRT (p = 0.2). For metastatic relapses, median PFS was 0.7 years for patients treated with focal radiotherapy (hypoFFRT, FFRT, spinal radiotherapy) versus 6.8 years for patients treated with CSI (p = 0.073). 15 patients achieved greater PFS after second radiotherapy (RT2) than after first radiotherapy (RT1). 27 patients (84 %) had surgery before re-irradiation. PFS was better for patients with GTR before RT2 (14.7 vs 6.7 months) (p = 0.05). 5 patients developed radionecrosis; only one required corticosteroids.

Conclusion

Re-irradiation at relapse is a safe, feasible and potentially curative treatment. Metastatic relapse may require CSI even when isolated and re-operated. For local relapses, considering conflicting results in the literature, a randomized trial is warranted to explore fractionated focal radiotherapy versus hypofractionated focal irradiation.

Ependymoma: a heterogeneous tumor of uncertain origin and limited therapeutic options

Ependymomas are tumors that typically occur with an age-based site preference, with adults harboring supratentorial and spinal tumors and pediatric tumors being mainly in the posterior fossa. Despite their similar histologic appearance, the prognosis varies significantly by age and tumor location, with a better prognosis in increasing age. The mainstay of treatment remains surgical excision with or without radiation therapy as the tumor biology is poorly understood and chemotherapy is generally considered to be ineffective. More recently, molecular biology data have increased our understanding of the genetic and epigenetic changes that drive these tumors, but still it will take a lot of effort to find effective chemotherapeutic regimens. Currently, we are trying to define a subset of tumors, for which radiation therapy can be avoided.

ABCB1 in children's brain tumours

Tumours of the central nervous system are the most common solid tumour, accounting for a quarter of the 1500 cases of childhood cancer diagnosed each year in the U.K. They are the most common cause of cancer-related death in children. Treatment consists of surgery followed by adjuvant chemotherapy and/or radiotherapy. Survival rates have generally increased, but many survivors suffer from radiotherapy-related neurocognitive and endocrine side effects as well as an increased risk of secondary cancer. Adjuvant chemotherapy is normally given in combination to circumvent chemoresistance, but several studies have demonstrated it to be ineffective in the absence of radiotherapy. The identification of children with drug-resistant disease at the outset could allow stratification of those that are potentially curable by chemotherapy alone. Ultimately, however, what is required is a means to overcome this drug resistance and restore the effectiveness of chemotherapy. Medulloblastomas and ependymomas account for over 30% of paediatric brain tumours. Advances in neurosurgery, adjuvant radiotherapy and chemotherapy have led to improvements in 5-year overall survival rates. There remain, however, significant numbers of medulloblastoma patients that have intrinsically drug-resistant tumours and/or present with disseminated disease. Local relapse in ependymoma is also common and has an extremely poor prognosis with only 25% of children surviving first relapse. Each of these is consistent with the acquisition of drug and radiotherapy resistance. Since the majority of chemotherapy drugs currently used to treat these patients are transport substrates for ATP-binding cassette sub-family B member 1 (ABCB1) we will address the hypothesis that ABCB1 expression underlies this drug resistance.

Posterior fossa tumors in infants and neonates

INTRODUCTION

Management of posterior fossa tumors in infants and neonates is challenging. The characteristics of the young babies make surgery very difficult, sometimes precluding a safe complete removal.

METHODS

A review of the literature was undertaken to examine the incidence, histology, surgical aspects, and prognosis of posterior fossa tumors in the first year of life. Therapeutical strategies of the most frequent tumor types are also discussed in detail.

RESULTS

Histology is dominated by tumors with aggressive behavior, such as medulloblastomas, atypical teratoid/rhabdoid tumors, and anaplastic ependymomas. The most important surgical considerations in small children are the small circulating blood volume; the poor thermoregulation; and incomplete maturation of the brain, of the skull, and of the soft tissue. Treatment toxicity is inversely related to the age of the patients. Radiation therapy is usually considered as contraindicated in young children, with few exceptions. Proton therapy is a promising tool, but access to this kind of treatment is still limited. The therapeutic limitations of irradiation render resection of this tumor and adjuvant chemotherapy often the only therapeutic strategy in many cases.

CONCLUSIONS

The overall prognosis remains dismal because of the prevalent aggressive histologies, the surgical challenges, and the limitations of adjuvant treatment. Nevertheless, the impressive improvements in anesthesiology and surgical techniques allow, in the vast majority of the cases, complete removal of the lesions with minor sequelae in high-volume referral pediatric centers.

Ependymoma in children under the age of 3 years: a report from the Canadian Pediatric Brain Tumour Consortium

The determination of optimal therapy for ependymoma (EP) in infants is ongoing. We describe the incidence, management and outcomes of Canadian infants with EP to discern potential future research questions. Of 579 cases registered in a national database of children <36 months of age diagnosed with a brain tumor from 1990 to 2005, inclusive, 75 (13 %) were EP. These cases were analyzed. A mean annual age-adjusted incidence rate of 4.6 per 100,000 children years was calculated. The male:female ratio was 1.77. Of the tumors, 80 % were infratentorial in location, 67 % were WHO grade II histology, and 29 % were metastatic at diagnosis. All patients underwent a surgical procedure. A complete resection of the tumor was achieved in 56 % of the cases; 43 % of these patients survive while 36 % of the patients with tumors less than completely resected survive. Initial therapy consisted of surgery alone in 23 % of patients, or surgery plus chemotherapy (37 %), radiation therapy (RT; 19 %), or both (21 %). Any use of RT increased with patient age. The 5-year EFS rates for patients in each of the four treatment groups was 22, 11.5, 46.2 and 64.8 %, respectively. For all patients the median survival was 63 ± 6 months and 5-year overall survival was 55 ± 6 %. Patients treated with surgery and chemotherapy alone were younger and had a lower rate of survival than older patients who were more often treated with radiation therapy containing regimens. Further study is needed to determine which patients are optimally served with these treatment modalities.

Ependymoma stem cells are highly sensitive to temozolomide in vitro and in orthotopic models

BACKGROUND

Ependymoma management remains challenging because of the inherent chemoresistance of this tumor. To determine whether ependymoma stem cells (SCs) might contribute to therapy resistance, we investigated the sensitivity of ependymoma SCs to temozolomide and etoposide.

METHODS

The efficacies of the two DNA damaging agents were explored in two ependymoma SC lines in vitro and in vivo models.

RESULTS

Ependymoma SC lines were highly sensitive to temozolomide and etoposide in vitro, but only temozolomide impaired tumor-initiation properties. Consistently, temozolomide but not etoposide showed significant antitumoral activity on ependymoma SC-driven subcutaneous and orthotopic xenografts by reducing the mitotic fraction. In vitro temozolomide at the EC50 (10 µM) induced accumulation of cells in the G2/M phase that was unexpectedly accompanied by downregulation of p27 and p21 without modulation of full-length p53 (FLp53). Differentiation-committed ependymoma SCs acquired resistance to temozolomide. Inhibition of proliferation was partly due to apoptosis, that occurred earlier in differentiated cells as compared to neurospheres. The activation of apoptosis correlated with an increase in p53β/γ isoforms without modulation of FLp53 under both serum-free and differentiation-promoting media. Incubation of cells in both conditions with temozolomide resulted in increased glioneuronal differentiation exhibiting elevated glial fibrillary acidic protein, galactosylceramidase, and βIII-tubulin expression compared to untreated controls. O(6)-methylguanine DNA methyltransferase (MGMT) transcript levels were very low in SCs, and were increased by treatment and, epigenetically, by differentiation through MGMT promoter unmethylation.

CONCLUSION

Ependymoma growth might be impaired by temozolomide through preferential depletion of a less differentiated, more tumorigenic, MGMT-negative cell population with stem-like properties.

Natural history and role of radiation in patients with supratentorial and infratentorial WHO grade II ependymomas: results from a population-based study

Patients with World Health Organization (WHO) grade II supratentorial ependymomas are commonly observed after gross total resection (GTR), although supporting data are limited. We sought to characterize the natural history of such tumors. We used the Surveillance, Epidemiology, and End Results program to identify 112 patients ages 0-77 diagnosed with WHO grade II ependymomas between 1988 and 2007, of whom 63 (56 %) and 49 (44 %) had supratentorial and infratentorial primaries, respectively. Inclusion criteria were strict to ensure patient homogeneity. Of 33 patients with supratentorial tumors after GTR, 18 (55 %) received adjuvant radiation therapy and 15 (45 %) did not. Ependymoma-specific mortality (ESM) was the primary endpoint. With a median follow up of 4.5 years, only 1 of 33 patients with supratentorial ependymoma died of their disease after GTR; the 5-year estimate of ESM in this population was 3.3 % (95 % CI 0.2-14.8 %). Among patients with infratentorial ependymomas after GTR, the 5-year estimate of ESM was 8.7 % (95 % CI 1.4-24.6 %). In patients with subtotally resected tumors, 5-year estimates of ESM in patients with supratentorial and infratentorial primaries were 20.1 % (95 % CI 8.0-36.2 %) and 12.3 % (95 % CI 2.9-28.8 %), respectively. Among the whole cohort, on both univariable and multivariable regression, extent of resection was predictive of ESM, while tumor location and use of radiation were not. After GTR, patients with WHO grade II supratentorial ependymomas have a very favorable natural history with low associated cancer-specific mortality. Observation, with radiation reserved as a salvage option, may be a reasonable postoperative strategy in this population.

Multidisciplinary management of pediatric intracranial ependymoma

Pediatric intracranial ependymoma is a rare disease representing approximately 7% of brain tumors in children aged 15 years or younger. Due to the relative rarity of these tumors, a clear standard therapy has been difficult to establish. The mainstay of treatment is surgical resection and the majority of data demonstrate improved outcome with gross total resection. The standard of care also includes postoperative radiation therapy for most patients with grade II and III tumors. Chemotherapy has been used in many capacities in this disease; however, its optimal role is yet to be defined. Current controversies such as treatment with surgery alone in completely resected tumors, use of chemotherapy for subtotally resected tumors and use of adjuvant postradiation chemotherapy are incorporated into the design of the current Children's Oncology Group clinical trial.

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

We analyzed the treatment outcomes of intracranial ependymomas in Korean children aged <18 years. Data for 96 patients were collected from five hospitals. Survival rates were calculated using the Kaplan-Meier method. Log-rank tests for univariate analyses and Cox regression model for multivariate analysis were conducted to identify prognostic factors for survival. The median age of the patients was 4 years (range, 0.3-17.9 years). The median follow-up was 55 months (range, 2-343 months). Age <3 years was an important factor for selecting adjuvant therapy after surgery. Among children aged <3 and ≥ 3 years, adjuvant radiotherapy (RT) was applied to 55 and 84 %, respectively, and adjuvant chemotherapy to 52 and 10 %, respectively. The 5 year local progression-free survival (LPFS), disease-free survival (DFS), and overall survival (OS) rates were 54, 52, and 79 %, respectively. Gross total resection was the most significant prognostic factor for all survival endpoints. Age ≥ 3 years and RT were significant prognostic factors for superior LPFS and DFS. However, the significance of age was lost in multivariate analysis for DFS. LPFS, DFS, and OS were superior in patients who started RT within 44 days after surgery (the median time) than in patients who started RT later in the patients aged ≥ 3 years. Postoperative RT was a strong prognostic factor for intracranial ependymomas. Our results suggest that early use of RT is an essential component of treatment, and should be considered in young children.

Phase II study of pre-irradiation chemotherapy for childhood intracranial ependymoma. Children's Cancer Group protocol 9942: a report from the Children's Oncology Group

PURPOSE

Standard therapy for childhood intracranial ependymoma is maximal tumor resection followed by involved-field irradiation. Although not used routinely, chemotherapy has produced objective responses in ependymoma, both at recurrence and in infants. Because the presence of residual tumor following surgery is consistently associated with inferior outcome, the potential impact of pre-irradiation chemotherapy was investigated.

METHODS

Between 1995 and 1999, the Children's Cancer Group undertook a Phase II trial of pre-irradiation chemotherapy in children 3-21 years of age with intracranial ependymoma and radiological evidence of post-operative residual tumor.

RESULTS

Of 84 patients, 41 had residual tumor, and were given four cycles of cisplatin-based chemotherapy prior to irradiation. Of 35 patients fully evaluable for response to chemotherapy, 14 (40%) demonstrated complete response, 6 (17%) partial response, 10 (29%) minor response or stable disease, and 5 (14%) demonstrated progressive tumor growth. For the entire group, 5-year overall survival (OS) and event-free survival (EFS) was 71 ± 6%, and 57 ± 6%, respectively. The pre-irradiation chemotherapy group demonstrated EFS comparable to that of patients with no residual tumor who received irradiation alone (55 ± 8% vs. 58 ± 9%, P = 0.45). Any benefit of chemotherapy was restricted to patients with greater than 90% tumor resection.

CONCLUSIONS

Children with near total resection of ependymoma may benefit from pre-irradiation chemotherapy. Patients with subtotal resection have inferior outcome despite responses to chemotherapy, and should be considered for second-look surgery prior to irradiation. Pediatr Blood Cancer 2012; 59: 1183-1189. © 2012 Wiley Periodicals, Inc.

Predictors of outcome in an AIEOP series of childhood ependymomas: a multifactorial analysis

Several molecular biomarkers have been suggested as predictors of outcome for pediatric ependymomas but deserve further validation in independent case series. We analyzed intracranial ependymomas belonging to a series of 60 patients prospectively treated according to the protocol sponsored by the Italian Association of Pediatric Hematology-Oncology. We used a tissue microarray to analyze nucleolin (NCL), cyclin-dependent kinase inhibitor 2A (CDKN2A), tumor protein 53 (TP53), and epidermal growth factor receptor (EGFR) by immunohistochemistry and by 1q gain by fluorescent in situ hybridization. The mRNA expression levels of EGFR, human telomerase reverse-transcriptase (HTERT), and Prominin 1 (PROM 1)/CD133 were evaluated by quantitative real-time PCR from cases with fresh-frozen tumor material available. Univariate and multivariate analyses of updated clinical data confirmed the prognostic significance of surgery (P < .01) and tumor grading (P < .05) for both relapse-free survival (RFS) and overall survival (OS). Among biomolecular markers, HTERT mRNA expression emerged with the strongest association with OS at multivariate analysis (hazard ratio [HR] = 9.9; P = .011); the 5-year OS was 84% versus 48% in the subgroups with HTERT median value <6 versus ≥ 6, respectively (P = .005). Five-year RFS was 46% versus 20% in the subgroups with low versus high NCL protein expression, respectively (P = .004), while multivariate Cox analyses gave suggestively high HRs for high versus low NCL (HR = 1.9; P = .090). The other genes tested were not significant at multivariate analyses, and genetic alterations of CDKN2A, TP53, EGFR, and HTERT loci were rare. The PROM1/CD133 cancer stem cell marker was strongly expressed at both RNA and protein levels in a substantial fraction of cases and was suggestively associated with a more indolent form of the disease. We conclude that NCL and HTERT represent the strongest prognostic biomarkers of RFS and OS, respectively, in our ependymoma case series.

Distinct disease-risk groups in pediatric supratentorial and posterior fossa ependymomas

No reliable classification is in clinical use for the therapeutic stratification of children with ependymoma, such that disease risk might be identified and patients treated to ensure a combination of maximal cure rates and minimal adverse therapeutic effects. This study has examined associations between clinicopathologic and cytogenetic variables and outcome in a trial cohort of children with ependymoma, with the aim of defining a practical scheme for stratifying this heterogeneous tumor. Intracranial ependymomas (n = 146) from children treated on the RT1 trial at St. Jude Children's Research Hospital were evaluated for the status of multiple pathological features. Interphase FISH (iFISH) defined the status of loci on chromosomes 1q (EXO1), 6q (LATS1) and 9, including 9p21 (CDKN2A). Data relating to these clinicopathological and cytogenetic variables were compared with survival data in order to model disease risk groups. Extent of surgical resection was a significant determinant of outcome in both supratentorial and infratentorial compartments. Tumor cell density and mitotic count were associated with outcome among children with posterior fossa ependymomas (n = 119). Among pathologic features, only brain invasion was associated with outcome in children with supratentorial ependymomas (n = 27). For posterior fossa tumors, gain of 1q was independently associated with outcome and in combination with clinicopathological variables defined both a two-tier and three-tier system of disease risk. Among children developing posterior fossa ependymomas treated with maximal surgical resection and conformal radiotherapy, key clinicopathological variables and chromosome 1q status can be used to define tiers of disease risk. In contrast, risk factors for pediatric supratentorial tumors are limited to sub-total resection and brain invasion.

Supratentorial ependymoma in children: to observe or to treat following gross total resection?

BACKGROUND

The standard treatment for ependymoma is surgical resection followed by postoperative irradiation to the local site. The role of radiation therapy in completely resected supratentorial ependymoma has been questioned over the past two decades.

PROCEDURE

Retrospective review of the medical records of all consecutively diagnosed supratentorial ependymoma patients at Children's Hospital Los Angeles between January 1999 and December 2009.

RESULTS

Ten patients (three females) were included. The median age at presentation was 5.6 years (range 1.8-15.6 years). Reviewed histology was anaplastic ependymoma in seven patients and cellular ependymoma in three patients. Gross total resection was achieved in six patients; five were observed and one received chemotherapy. In the four patients who underwent subtotal resection, one was observed, two received local irradiation and one received irradiation and chemotherapy. The median length of follow up was 43 (range 22-81) months. Four relapses were observed; two patients who underwent initial gross total resection. All patients who underwent gross total resection were alive at the time of preparation of this article. The 5-year progression-free and overall survival rates were 53 ± 19% and 86 ± 13% respectively.

CONCLUSIONS

Radiation therapy was avoided in five patients following gross total resection, four of whom had anaplastic histology. In some children with completely resected supratentorial ependymoma, surgery alone may be an acceptable treatment option.

Long-term survival following gross total resection of pediatric supratentorial ependymomas without adjuvant therapy

Pediatric supratentorial ependymoma is very rare. In pediatric patients with supratentorial ependymoma, surgery alone may be an acceptable treatment when postoperative imaging confirms a gross total resection. Surgical resection is the standard and the most important treatment for ependymoma. The role of radiation therapy and/or chemotherapy following a gross total resection of supratentorial ependymoma has been uncertain. We report 2 cases of pediatric supratentorial ependymomas treated by gross total resection without postoperative adjuvant therapy. The first patient was a 7-year-old girl who presented with motor weakness and a hemiconvulsion of the right leg. Magnetic resonance imaging (MRI) revealed a large heterogeneously enhanced tumor in the left frontal lobe. The second patient was an 8-year-old girl who presented with headache. MRI revealed a huge heterogeneously enhanced tumor in the left frontal lobe. Gross total resection was achieved in both patients. Postoperative radiotherapy and chemotherapy were avoided following gross total resection. Histologically, the lesions demonstrated grade II ependymoma and anaplastic ependymoma, respectively. After follow-up of 120 months, neither patient had recurrence or dissemination. These results suggest that patients with pediatric supratentorial ependymoma treated by gross total resection alone have a favorable outcome, and postoperative radiotherapy and chemotherapy may be avoided.

Pediatric infratentorial ependymoma: prognostic significance of anaplastic histology

Pediatric infratentorial ependymomas are difficult to cure. Despite the availability of advanced therapeutic modalities for brain tumors, total surgical resection remains the most important prognostic factor. Recently, histological grade emerged as an independent prognostic factor for intracranial ependymoma. We retrospectively reviewed the treatment outcome of 33 pediatric patients with infratentorial ependymoma. Progression-free survival (PFS) and overall survival (OS) rates were calculated and relevant prognostic factors were analyzed. Fourteen patients (42%) were under the age of 3 at diagnosis. Gross total resection was achieved in 16 patients (49%). Anaplastic histology was found in 13 patients (39%). Adjuvant therapies were delayed until progression in 12 patients (36%). Actuarial PFS rates were 64% in the first year and 29% in the fifth year. Actuarial OS rates were 91% in the first year and 71% in the fifth year. On univariate analysis, brainstem invasion (P = 0.047), anaplastic histology (P = 0.004), higher mitotic count (P = 0.001), and higher Ki-67 index (P = 0.004) were significantly related to a shorter PFS. Gross total resection (P = 0.029) and a greater age at diagnosis (P = 0.033) were significantly related to a longer PFS. On multivariate analysis, anaplastic histology alone was significantly related to a shorter PFS (P = 0.023). Gross total resection (P = 0.039) was significantly related to a longer overall survival (OS) on multivariate analysis. Anaplastic histology and gross total resection were the most important clinical factors affecting PFS and OS, respectively. Anaplastic histology, mitotic count, and Ki-67 index can be used as universal and easily available prognostic parameters in infratentorial ependymomas.