Treatment and outcome of children with relapsed ependymoma: a multi-institutional retrospective analysis

Respective Roles of Surgery, Chemotherapy, and Radiation Therapy for Recurrent Pediatric and Adolescent Ependymoma: A National Multicentric Study

PURPOSE

Half of the children and adolescents treated for intracranial ependymoma experience recurrences that are not managed in a standardized manner. This study aimed to retrospectively evaluate recurrence treatments.

METHODS AND MATERIALS

We assessed overall survival (OS) and progression-free survival (PFS) after a first relapse in a population of patients from the Pediatric Ependymoma Photons Protons and Imaging study (PEPPI study) who were treated with surgery and radiation therapy in French Society of Childhood Cancer reference centers between 2000 and 2013. Data were analyzed using the Cox model as well as a landmark analysis at 4 months that accounted for the guarantee-time bias.

RESULTS

The median follow-up of the whole population of 202 patients was 105.1 months, with a 10-year OS of 68.2% and PFS of 45.5%. Among the 100 relapse cases, 68.0% were local relapses, 20.0% were metastatic, and 12.0% were combined (local and metastatic). Relapses were treated by surgery (n = 79) and/or reirradiation (n = 52) and/or chemotherapy (n = 22). The median follow-up after relapse was 77.8 months. The OS and PFS at 5 years were 43.1% and 16.2%, respectively. After surgery or radiation therapy of the first relapse, OS and PFS were more favorable, whereas treatments that included chemotherapy with or without focal treatment were associated with worse OS and PFS. In the multivariate analysis, stereotactic hypofractionated reirradiation after surgery was associated with a significantly better outcome (OS, P = .030; PFS, P = .008) and chemotherapy with a worse outcome (OS, P = .028; PFS, P = .033).

CONCLUSIONS

This analysis of relapse treatments within the PEPPI study determined that irrespective of whether the relapse was localized or metastatic, treatments that included surgery and/or reirradiation had better outcomes.

Multi-omic approach identifies hypoxic tumor-associated myeloid cells that drive immunobiology of high-risk pediatric ependymoma

Ependymoma (EPN) is a devastating childhood brain tumor. Single-cell analyses have illustrated the cellular heterogeneity of EPN tumors, identifying multiple neoplastic cell states including a mesenchymal-differentiated subpopulation which characterizes the PFA1 subtype. Here, we characterize the EPN immune environment, in the context of both tumor subtypes and tumor cell subpopulations using single-cell sequencing (scRNAseq, n = 27), deconvolution of bulk tumor gene expression (n = 299), spatial proteomics (n = 54), and single-cell cytokine release assays (n = 12). We identify eight distinct myeloid-derived subpopulations from which a group of cells, termed hypoxia myeloid cells, demonstrate features of myeloid-derived suppressor cells, including IL6/STAT3 pathway activation and wound healing ontologies. In PFA tumors, hypoxia myeloid cells colocalize with mesenchymal-differentiated cells in necrotic and perivascular niches and secrete IL-8, which we hypothesize amplifies the EPN immunosuppressive microenvironment. This myeloid cell-driven immunosuppression will need to be targeted for immunotherapy to be effective in this difficult-to-cure childhood brain tumor.

Nuclear condensates of YAP fusion proteins alter transcription to drive ependymoma tumourigenesis

Nuclear localization of HIPPO-YAP fusion proteins has been implicated in supratentorial ependymoma development. Here, unexpectedly, we find that liquid-liquid phase separation, rather than nuclear localization, of recurrent patient-derived YAP fusions, YAP-MAMLD1 and C11ORF95-YAP, underlies ependymoma tumourigenesis from neural progenitor cells. Mutagenesis and chimaera assays demonstrate that an intrinsically disordered region promotes oligomerization of the YAP fusions into nuclear, puncta-like, membrane-less condensates. Oligomerization and nuclear condensates induced by YAP fusion with a coiled-coil domain of transcriptional activator GCN4 also promote ependymoma formation. YAP-MAMLD1 concentrates transcription factors and co-activators, including BRD4, MED1 and TEAD, in condensates while excluding transcriptional repressive PRC2, and induces long-range enhancer-promoter interactions that promote transcription and oncogenic programmes. Blocking condensate-mediated transcriptional co-activator activity inhibits tumourigenesis, indicating a critical role of liquid phase separation for YAP fusion oncogenic activity in ependymoma. YAP fusions containing the intrinsically disordered region features are common in human tumours, suggesting that nuclear condensates could be targeted to treat YAP-fusion-induced cancers.

Outcomes following management of relapsed pediatric posterior fossa ependymoma in the molecular era

PURPOSE

The overall survival and prognostic factors for children with multiply recurrent posterior fossa ependymoma are not well understood. We aimed to assess prognostic factors associated with survival for relapsed pediatric posterior fossa ependymoma.

METHODS

An institutional database was queried for children with a primary diagnosis of posterior fossa ependymoma from 2000 to 2019. Kaplan-Meier survival analysis and Cox-proportional hazard regression were used to assess the relationship between treatment factors and overall survival.

RESULTS

There were 60 patients identified; molecular subtype was available for 56, of which 49 (87.5%) were PF-A and 7 (12.5%) were PF-B. Relapse occurred in 29 patients (48%) at a mean time of 24 months following primary resection. Median 50% survival was 12.3 years for all patients and 3.3 years following diagnosis of first relapsed disease. GTR was associated with significantly improved survival following primary resection (HR 0.373, 95% CI 0.14-0.96). Presence of recurrent disease was significantly associated with worse survival (p < 0.0001). At recurrent disease diagnosis, disseminated disease was a negative prognostic factor (HR 11.0 95% CI 2.7-44) while GTR at first relapse was associated with improved survival HR 0.215 (95% CI: 0.048-0.96, p = 0.044). Beyond first relapse, the impact of GTR was not significant on survival, though surgery compared to no surgery was favorable with HR 0.155 (95% CI: 0.04-0.59).

CONCLUSIONS

Disseminated disease at recurrence and extent of resection for first relapsed disease were important prognostic factors. Surgery compared to no surgery was associated with improved survival for the multiply recurrent ependymoma cohort.

Role of Radiotherapy in Patients With Relapsed Medulloblastoma

During the last three decades, the management of medulloblastoma (MBL) has made enormous progress with a multidisciplinary approach, incorporating surgery, radiotherapy (RT), and chemotherapy. Despite this improvement, 20%-30% of patients with MBL remain at risk of disease recurrence, with its relapse being possibly fatal. To date, the salvage treatment for relapse remains challenging, and various approaches have been suggested for the retreatment. In this review, I have described the characteristics of patients with relapsed MBL, patterns of relapse and the most commonly prescribed treatment. Further, I have reviewed the studies on re-irradiation and its associated issues to conclusively suggest the RT recommendations for patients with relapsed MBL.

Immunohistochemical assessment and clinical, histopathologic, and molecular correlates of membranous somatostatin type-2A receptor expression in high-risk pediatric central nervous system tumors

INTRODUCTION

177Lu-DOTATATE, a radionuclide therapy that binds somatostatin type-2A receptors (SST2A), has demonstrated efficacy in neuroendocrine tumors and evidence of central nervous system (CNS) penetration, supporting potential expansion within pediatric neuro-oncology. Understanding the prevalence of SST2A expression across pediatric CNS tumors is essential to identify patients who may benefit from somatostatin receptor-targeted therapy and to further elucidate the oncogenic role of SST2A.

METHODS

SST2A immunohistochemistry (IHC) was performed on tumor specimens and interpreted by an experienced pathologist (blinded), utilizing semi-quantitative scoring of membranous expression within viable tumor. Immunoreactive cell percentage was visually scored as 0 (none), 1 (<10%), 2 (10-50%), 3 (51-80%), or 4 (>80%). Staining intensity was scored as 0 (none), 1 (weak), 2 (moderate), or 3 (strong). Combined scores for each specimen were calculated by multiplying percent immunoreactivity and staining intensity values (Range: 0-12).

RESULTS

A total of 120 tumor samples from 114 patients were analyzed. Significant differences in SST2A IHC scores were observed across histopathologic diagnoses, with consistently high scores in medulloblastoma (mean ± SD: 7.5 ± 3.6 [n=38]) and meningioma (5.7 ± 3.4 [n=15]), compared to minimal or absent expression in ATRT (0.3 ± 0.6 [n=3]), ETMR (1.0 ± 0 [n=3]), ependymoma (grades I-III; 0.2 ± 0.7 [n=27]), and high-grade glioma (grades III-IV; 0.4 ± 0.7 [n=23]). Pineoblastoma (3.8 ± 1.5 [n=4]) and other embryonal tumors (2.0 ± 4.0 [n=7]) exhibited intermediate, variable expression. Among medulloblastomas, SST2A IHC scores were higher in non-SHH (8.5 ± 3.1) than SHH (5.0 ± 3.3) molecular subgroups (p=0.033). In a subset of paired primary and recurrent specimens from four patients, SST2A IHC scores remained largely unchanged.

DISCUSSION

High membranous SST2A expression was demonstrated in medulloblastoma, meningioma, and some rarer embryonal tumors with potential diagnostic, biologic, and therapeutic implications. Somatostatin receptor-targeted therapy such as 177Lu-DOTATATE deserves further investigation in these highly SST2A-expressing pediatric CNS tumors.

Apatinib and temozolomide in children with recurrent ependymoma: A case report

RATIONALE

Outcomes remain poor in children with recurrent ependyomams (rEPNs), despite advances in surgery and radiotherapy. Systemic therapeutic options are limited, given the low response to chemotherapy and targeted drugs. There is an urgent need for efective pharmacotherapy. Apatinib is a multitarget tyrosine kinase inhibitor, which has been reported to exhibit broad antitumor profiles. However, its effects on rEPNs have not been reported thus far.

PATIENT CONCERNS

We present a 5-year-old recurrent ependyomam patient benefting from apatinib and temozolomide. The patient was diagnosed with ependyomam in January 2016 and treated with surgery and radiotherapy. After surgery, the patient walked with an mild unsteady gait. He was diagnosed with recurrence in November 2018 following which he was treated with reoperation, reirradiation and chemotherapy (etopside, cisplatin, and temozolomide [TMZ]). The patients increased gait instability in April 2019.

DIAGNOSES

Magnetic resonance imaging (MRI) showed progression of the disease. The lession at the left edge of the fourth ventricle and cerebellar peduncles was significantly increased.

INTERVENTIONS

The patient was administer TMZ (200 mg/m2/d, d1-5, 28 days as a cycle) + apatinib (250 mg, every other day). Twelve cycle of TMZ and apatinib were given.

OUTCOMES

The tumor significantly shrank during the patient received TMZ and apatinib. After 9 months of medication, MRI revealed a nearly complete response However, the tumor progressed on May 5, 2020. From the beginning of the application of TMZ and apatinib, the progression-free survival was 1 year and the survival time was 19 months. Grade 1 leukocytopenia was observed without other adverse effects.

CONCLUSION

Apatinib and temozolomide treatment with mild side effects may be a new option for children with recurrent ependyomams.

Ependymoma: Evaluation and Management Updates

PURPOSE OF REVIEW

To review state of art and relevant advances in the molecular genetics and management of ependymomas of children and adults.

RECENT FINDINGS

Ependymomas may occur either in the brain or in the spinal cord. Compared with intracranial ependymomas, spinal ependymomas are less frequent and exhibit a better prognosis. The new WHO classification of CNS tumors of 2021 has subdivided ependymomas into different histomolecular subgroups with different outcome. The majority of studies have shown a major impact of extent of resection; thus, a complete resection must be performed, whenever possible, at first surgery or at reoperation. Conformal radiotherapy is recommended for grade 3 or incompletely resected grade II tumors. Proton therapy is increasingly employed especially in children to reduce the risk of neurocognitive and endocrine sequelae. Craniospinal irradiation is reserved for metastatic disease. Chemotherapy is not useful as primary treatment and is commonly employed as salvage treatment for patients failing surgery and radiotherapy. Standard treatments are still the mainstay of treatment: the discovery of new druggable pathways will hopefully increase the therapeutic armamentarium in the near future.

Phase II study of intravenous etoposide in patients with relapsed ependymoma (CNS 2001 04)

Background

Relapsed ependymoma has a dismal prognosis, and the role of chemotherapy at relapse remains unclear. This study prospectively evaluated the efficacy of intensive intravenous (IV) etoposide in patients less than 21 years of age with relapsed intracranial ependymoma (NCT00278252).

Methods

This was a single-arm, open-label, phase II trial using Gehan's two-stage design. Patients received IV etoposide 100 mg/m2 on days 1-3, 8-10, and 15-17 of each 28-day cycle, up to maximum of 6 cycles. Primary outcome was radiological response after 3 cycles. Pharmacokinetic analysis was performed in 10 patients.

Results

Twenty-five patients were enrolled and included in the intention-to-treat (ITT) analysis. Three patients were excluded in per-protocol (PP) analysis. After 3 cycles of etoposide, 5 patients (ITT 20%/PP 23%) had a complete response (CR), partial response (PR), or objective response (OR). Nine patients (ITT 36%/PP 41%,) had a best overall response of CR, PR, or OR. 1-year PFS was 24% in ITT and 23% in PP populations. 1-year OS was 56% and 59%, 5-year OS was 20% and 18%, respectively, in ITT and PP populations. Toxicity was predominantly hematological, with 20/25 patients experiencing a grade 3 or higher hematological adverse event.

Conclusions

This study confirms the activity of IV etoposide against relapsed ependymoma, however, this is modest, not sustained, and similar to that with oral etoposide, albeit with increased toxicity. These results confirm the dismal prognosis of this disease, provide a rationale to include etoposide within drug combinations, and highlight the need to develop novel treatments for recurrent ependymoma.

Molecular Classification and Therapeutic Targets in Ependymoma

Ependymoma is a biologically diverse tumor wherein molecular classification has superseded traditional histological grading based on its superior ability to characterize behavior, prognosis, and possible targeted therapies. The current, updated molecular classification of ependymoma consists of ten distinct subgroups spread evenly among the spinal, infratentorial, and supratentorial compartments, each with its own distinct clinical and molecular characteristics. In this review, the history, histopathology, standard of care, prognosis, oncogenic drivers, and hypothesized molecular targets for all subgroups of ependymoma are explored. This review emphasizes that despite the varied behavior of the ependymoma subgroups, it remains clear that research must be performed to further elucidate molecular targets for these tumors. Although not all ependymoma subgroups are oncologically aggressive, development of targeted therapies is essential, particularly for cases where surgical resection is not an option without causing significant morbidity. The development of molecular therapies must rely on building upon our current understanding of ependymoma oncogenesis, as well as cultivating transfer of knowledge based on malignancies with similar genomic alterations.

Adult Posterior Fossa Anaplastic Ependymoma, Case Series and Literature Review

OBJECTIVE

Ependymomas are rare central nervous system tumors. The current treatment strategy is gross total tumor removal. Whether adjuvant therapy will be beneficial is controversial. We retrospectively analyzed 3 cases of World Health Organization (WHO) grade III posterior fossa anaplastic ependymomas treated with different treatment modalities. We aimed to identify possible treatment options for infratentorial WHO grade III anaplastic ependymoma in adults.

METHODS

We performed a retrospective analysis of 3 patients diagnosed with infratentorial anaplastic ependymomas in our institution from 2016 to 2020. The demographic data were documented. This case series of 3 patients does not meet the Department of Health and Human Services definition of research and does not need Institutional Review Board approval. All patients' informed consents have been obtained.

RESULTS

One patient underwent subtotal tumor resection combined with adjuvant radiotherapy and Gamma Knife radiosurgery while the other 2 patients underwent gross total tumor removal combined with Gamma Knife radiosurgery or adjuvant radiotherapy. Tumors recurred in the first patient 20 months later, while the other 2 patents did not develop recurrence. The modified Rankin scale scores of these patients were 1, 0, and 0. All patients are followed up with regular magnetic resonance imaging at our facility.

CONCLUSIONS

The strategy for treating WHO grade III anaplastic ependymomas is controversial, but gross total tumor resection remains the key element. Adjuvant stereotactic radiosurgery after tumor removal might be considered if radiotherapy is not an option. The role of chemotherapy is unclear, and the use of chemotherapy should be tailored to individual patients.

Oral etoposide as a single agent in childhood and young adult cancer in England: Still a poorly evaluated palliative treatment

BACKGROUND

Oral etoposide is commonly used in palliative treatment of childhood and young adult cancer without robust evidence. We describe a national, unselected cohort of young people in England treated with oral etoposide using routinely collected, population-level data.

METHODS

Patients aged under 25 years at cancer diagnosis (1995-2017) with a treatment record of single-agent oral etoposide in the Systemic AntiCancer Dataset (SACT, 2012-2018) were identified, linked to national cancer registry data using NHS number and followed to 5 January 2019. Overall survival (OS) was estimated for all tumours combined and by tumour group. A Cox model was applied accounting for age, sex, tumour type, prior and subsequent chemotherapy.

RESULTS

Total 115 patients were identified during the study period. Mean age was 11.8 years at cancer diagnosis and 15.5 years at treatment with oral etoposide. Median OS was 5.5 months from the start of etoposide; 13 patients survived beyond 2 years. Survival was shortest in patients with osteosarcoma (median survival 3.6 months) and longest in CNS embryonal tumours (15.5 months). Across the cohort, a median of one cycle (range one to nine) of etoposide was delivered. OS correlated significantly with tumour type and prior chemotherapy, but not with other variables.

CONCLUSIONS

This report is the largest series to date of oral etoposide use in childhood and young adult cancer. Most patients treated in this real world setting died quickly. Despite decades of use, there are still no robust data demonstrating a clear benefit of oral etoposide for survival.

Systemic chemotherapy of pediatric recurrent ependymomas: results from the German HIT-REZ studies

PURPOSE

Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN.

METHODS

Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated.

RESULTS

Median age at first recurrence was 7.6 years (IQR: 4.0-13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3-20.0) and 36.9 months (CI 29.7-53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74-1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found.

CONCLUSION

No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation.

Outcomes after first relapse of childhood intracranial ependymoma

BACKGROUND

Ependymoma is the third most common malignant CNS tumor in children. Despite multimodal therapy, prognosis of relapsed ependymoma remains poor. Approaches to therapy for relapsed ependymoma are varied. We present a single-institution retrospective review of the outcomes after first relapse of intracranial ependymoma in children.

PROCEDURE

We performed a retrospective, IRB-approved chart review of patients with recurrent intracranial ependymoma treated at Dana-Farber/Boston Children's Cancer and Blood Disorders Center from 1990 to 2019.

RESULTS

Thirty-four patients with relapsed intracranial ependymoma were identified. At initial diagnosis, 11 patients had supratentorial disease, 22 with posterior fossa disease and one with metastatic disease. Median time-to-first relapse was 14.9 months from initial diagnosis (range 1.4-52.5). Seven patients had metastatic disease at first relapse. Gross total resection (GTR) was associated with improved 5-year progression-free survival (PFS) relative to subtotal resection (STR) and no surgery (p = .005). Localized disease at relapse was associated with improved 5-year overall survival (OS) when compared to metastatic disease (p = .02). Irradiation at first relapse seemed to delay progression but was not associated with statistically prolonged PFS or OS. Tumor location, histology, and chromosomal 1q status did not impact outcome at first relapse, although available molecular data were limited making definitive conclusions difficult. Median time-to-second relapse was 10 months (range 0.7-124). Five-year PFS and OS after first relapse were 19.9% and 45.1%, respectively. Median PFS and OS were 10.0 and 52.5 months after first relapse, respectively.

CONCLUSIONS

Relapsed intracranial ependymoma has a poor prognosis despite multimodal therapy. Novel therapeutic strategies are desperately needed for this disease.

Local and systemic therapy of recurrent ependymoma in children and adolescents: short- and long-term results of the E-HIT-REZ 2005 study

BACKGROUND

Survival in recurrent ependymomas in children and adolescents mainly depends on the extent of resection. Studies on repeated radiotherapy and chemotherapy at relapse have shown conflicting results.

METHODS

Using data from the German multi-center E-HIT-REZ-2005 study, we examined the role of local therapy and the efficacy of chemotherapy with blockwise temozolomide (TMZ) in children and adolescents with recurrent ependymomas.

RESULTS

Fifty-three patients with a median age of 6.9 years (1.25-25.4) at first recurrence and a median follow-up time of 36 months (2-115) were recruited. Gross- and near-total resection (GTR/NTR) were achieved in 34 (64.2%) patients and associated with a markedly improved 5-year overall survival (OS) of 48.7% vs. 5.3% in less than GTR/NTR. Radiotherapy showed no improvement in OS following complete resection (OS: 70 (CI: 19.9-120.1) vs. 95 (CI: 20.7-169.4) months), but an advantage was found in less than GTR/NTR (OS: 22 (CI: 12.7-31.3) vs. 7 (CI: 0-15.8) months). Following the application of TMZ, disease progression was observed in most evaluable cases (18/21). A subsequent change to oral etoposide and trofosfamide showed no improved response. PF-A EPN were most abundant in relapses (n = 27). RELA-positive EPN (n = 5) had a 5-year OS of 0%.

CONCLUSION

The extent of resection is the most important predictor of survival at relapse. Focal re-irradiation is a useful approach if complete resection cannot be achieved, but no additional benefit was seen after GTR/NTR. Longer-term disease stabilization (>6 months) mediated by TMZ occurred in a small number of cases (14.3%).

Phase I study of intraventricular infusions of autologous ex vivo expanded NK cells in children with recurrent medulloblastoma and ependymoma

BACKGROUND

Recurrent pediatric medulloblastoma and ependymoma have a grim prognosis. We report a first-in-human, phase I study of intraventricular infusions of ex vivo expanded autologous natural killer (NK) cells in these tumors, with correlative studies.

METHODS

Twelve patients were enrolled, 9 received protocol therapy up to 3 infusions weekly, in escalating doses from 3 × 106 to 3 × 108 NK cells/m2/infusion, for up to 3 cycles. Cerebrospinal fluid (CSF) was obtained for cellular profile, persistence, and phenotypic analysis of NK cells. Radiomic characterization on pretreatment MRI scans was performed in 7 patients, to develop a non-invasive imaging-based signature.

RESULTS

Primary objectives of NK cell harvest, expansion, release, and safety of 112 intraventricular infusions of NK cells were achieved in all 9 patients. There were no dose-limiting toxicities. All patients showed progressive disease (PD), except 1 patient showed stable disease for one month at end of study follow-up. Another patient had transient radiographic response of the intraventricular tumor after 5 infusions of NK cell before progressing to PD. At higher dose levels, NK cells increased in the CSF during treatment with repetitive infusions (mean 11.6-fold). Frequent infusions of NK cells resulted in CSF pleocytosis. Radiomic signatures were profiled in 7 patients, evaluating ability to predict upfront radiographic changes, although they did not attain statistical significance.

CONCLUSIONS

This study demonstrated feasibility of production and safety of intraventricular infusions of autologous NK cells. These findings support further investigation of locoregional NK cell infusions in children with brain malignancies.

Reevaluating surgery and re-irradiation for locally recurrent pediatric ependymoma—a multi-institutional study

Background

The goal of this study was to evaluate extent of surgical resection, and timing and volume of re-irradiation, on survival for children with locally recurrent ependymoma.

Methods

Children with locally recurrent ependymoma treated with a second course of fractionated radiotherapy (RT2) from 6 North American cancer centers were reviewed. The index time was from the start of RT2 unless otherwise stated.

Results

Thirty-five patients were included in the study. The median doses for first radiation (RT1) and RT2 were 55.8 and 54 Gy, respectively. Median follow-up time was 5.6 years. Median overall survival (OS) for all patients from RT2 was 65 months. Gross total resection (GTR) was performed in 46% and 66% of patients prior to RT1 and RT2, respectively. GTR prior to RT2 was independently associated with improved progression-free survival (PFS) for all patients (HR 0.41, P = 0.04), with an OS benefit (HR 0.26, P = 0.03) for infratentorial tumors. Median PFS was superior with craniospinal irradiation (CSI) RT2 (not reached) compared to focal RT2 (56.9 months; log-rank P = 0.03). All distant failures (except one) occurred after focal RT2. Local failures after focal RT2 were predominantly in patients with less than GTR pre-RT2.

Conclusions

Patients with locally recurrent pediatric ependymoma should be considered for re-treatment with repeat maximal safe resection (ideally GTR) and CSI re-irradiation, with careful discussion of the potential side effects of these treatments.

A retrospective analysis of recurrent pediatric ependymoma reveals extremely poor survival and ineffectiveness of current treatments across central nervous system locations and molecular subgroups

BACKGROUND

Relapse occurs in 50% of pediatric ependymoma cases and has poor prognosis. Few studies have investigated the clinical progress of relapsed disease, and treatment lacks a standardized approach.

METHODS AND MATERIALS

We analyzed 302 pediatric ependymoma cases. Tumor, demographic, and treatment variables were investigated for association with relapse risk, time to recurrence, and survival after relapse. DNA methylation profiling was performed for 135/302 cases, and predominant subgroups were EPN_PFA (n = 95) and EPN_RELA (n = 24). Chromosome 1q status was ascertained for 185/302 cases by fluorescent in-situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA), and DNA methylation profiles.

RESULTS

Sixty-two percent of cases relapsed, with a median of two recurrences with no difference between posterior fossa and supratentorial locations (66% vs 55% relapse rate). One hundred seventeen (38%) cases relapsed within two years and five (2%) beyond 10 years. The late relapses were clinically heterogeneous. Tumor grade and treatment affected risk and time to relapse variably across subgroups. After relapse, surgery and irradiation delayed disease progression with a minimal impact on survival across the entire cohort. In the EPN_PFA and EPN_RELA groups, 1q gain was independently associated with relapse risk (subhazard ratio [SHR] 4.307, P = 0.027 and SHR 1.982, P = 0.010, respectively) while EPN_PFA had increased relapse risk compared with EPN_RELA (SHR = 0.394, P = 0.018).

CONCLUSIONS

Recurrent pediatric ependymoma is an aggressive disease with poor outcomes, for which current treatments are inadequate. We report that chromosome 1q gain increases relapse risk in common molecular subgroups in children but a deeper understanding of the underlying biology at relapse and novel therapeutic approaches are urgently needed.

Is H3K27me3 status really a strong prognostic indicator for pediatric posterior fossa ependymomas? A single surgeon, single center experience

PURPOSE

Posterior fossa ependymomas (PFE) are among the most frequently occurring solid tumors in children. Their definitive treatment is surgical excision and adjuvant radio-chemotherapy. This study aimed to investigate prognostic effects of age, H3K27me3 status, extent of resection, radiation treatment (RT), Ki67 index, WHO grade, and ATRX and H3K27M mutations in PFE patients.

METHODS

This retrospective study included 42 pediatric patients with PFE who had undergone operation at our institution between 1996 and 2018. Patient demographics and treatment information were obtained from patient notes. Information on radiological location of tumors (median vs paramedian), extent of tumor resection, and recurrence was obtained from preoperative and postoperative magnetic resonance imaging. Formalin-fixed paraffin-embedded tumor samples were evaluated for H3K27me3 immunostaining, Ki67 index, WHO grades, and ATRX and H3K27M mutations. Tumor samples with global reduction in H3K27me3 were grouped as posterior fossa ependymoma group A (PFA) and those with H3K27me3 nuclear immunopositivity as posterior fossa ependymoma group B (PFB). We evaluated the cohort's 5-year progression-free survival (PFS) and overall survival (OS).

RESULTS

There were 20 (47.6%) female and 22 (52.4%) male patients in the cohort. The mean age of patients was 4.4 (range, 0.71-14.51) years. Overall, tumors in 31 (73.8%) and 11 (26.2%) patients were found to be PFA and PFB, respectively. There was no statistically significant age or sex difference between PFA and PFB. All patients received chemotherapy, whereas only 28 (66.6%) received RT. The WHO grades of PFA were statistically higher than those of PFB. There was no significant difference between PFA and PFB in terms of extent of resection, disease recurrence, and survival parameters. Nine of 42 tumor samples had ATRX mutations. One patient with PFA showed H3K27M mutation. Age, WHO grade, H3K27me3 status, and RT had no effect on patients' PFS and OS. Patients with total surgical excisions had significantly better PFS and OS rates. Those with Ki67 < 50% also had better OS rates.

CONCLUSIONS

Determining H3K27me3 status by immunohistochemistry is a widely accepted method for molecular subgrouping of PFEs. Most of the reports in the literature state that molecular subgroups of PFEs have significantly different clinical outcomes. However, in our present series, we have shown that the extent of surgical excision is still the most important prognostic indicator in PFEs. We also conclude that the prognostic effect of H3K27me3 status-based molecular subgrouping may be minimized with a more aggressive surgical strategy followed in PFAs.

Phase I study of gene-mediated cytotoxic immunotherapy with AdV-tk as adjuvant to surgery and radiation for pediatric malignant glioma and recurrent ependymoma

BACKGROUND

Gene-mediated cytotoxic immunotherapy (GMCI) is a tumor-specific immune stimulatory strategy implemented through local delivery of aglatimagene besadenovec (AdV-tk) followed by anti-herpetic prodrug. GMCI induces T-cell dependent tumor immunity and synergizes with radiotherapy. Clinical trials in adult malignant gliomas demonstrated safety and potential efficacy. This is the first trial of GMCI in pediatric brain tumors.

METHODS

This phase I dose escalation study was conducted to evaluate GMCI in patients 3 years of age or older with malignant glioma or recurrent ependymoma. AdV-tk at doses of 1 × 1011 and 3 × 1011 vector particles (vp) was injected into the tumor bed at the time of surgery followed by 14 days of valacyclovir. Radiation started within 8 days of surgery, and if indicated, chemotherapy began after completion of valacyclovir.

RESULTS

Eight patients (6 glioblastoma, 1 anaplastic astrocytoma, 1 recurrent ependymoma) were enrolled and completed therapy: 3 on dose level 1 and 5 on dose level 2. Median age was 12.5 years (range 7-17) and Lansky/Karnofsky performance scores were 60-100. Five patients had multifocal/extensive tumors that could not be resected completely and 3 had gross total resection. There were no dose-limiting toxicities. The most common possibly GMCI-related adverse events included Common Terminology Criteria for Adverse Events grade 1-2 fever, fatigue, and nausea/vomiting. Three patients, in dose level 2, lived more than 24 months, with 2 alive without progression 37.3 and 47.7 months after AdV-tk injection.

CONCLUSIONS

GMCI can be safely combined with radiation therapy with or without temozolomide in pediatric patients with brain tumors and the present results strongly support further investigation.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov NCT00634231.

Craniospinal irradiation as part of re-irradiation for children with recurrent intracranial ependymoma

BACKGROUND

The goal of this study was to evaluate outcomes in children with relapsed, molecularly characterized intracranial ependymoma treated with or without craniospinal irradiation (CSI) as part of a course of repeat radiation therapy (re-RT).

METHODS

This was a retrospective cohort study of 31 children. Patients with distant relapse received CSI as part of re-RT. For patients with locally recurrent ependymoma, those treated before 2012 were re-irradiated with focal re-RT. In 2012, institutional practice changed to offer CSI, followed by boost re-RT to the site of resected or gross disease.

RESULTS

Median follow-up was 5.5 years. Of 9 patients with distant relapse after initial RT, 2-year freedom from progression (FFP) and overall survival (OS) were 12.5% and 62.5%, respectively. There were 22 patients with local failure after initial RT. In these patients, use of CSI during re-RT was associated with improvement in 5-year FFP (83.3% with CSI vs 15.2% with focal re-RT only, P = 0.030). In the subgroup of patients with infratentorial primary disease, CSI during re-RT also improved 5-year FFP (100% with CSI, 10.0% with focal re-RT only, P = 0.036). Twenty-three patients had known molecular status; all had posterior fossa group A tumors (n = 17) or tumors with a RELA (v-rel avian reticuloendotheliosis viral oncogene homolog A) fusion (n = 6). No patient developed radiation necrosis after fractionated re-RT, though almost all survivors required assistance throughout formal schooling. Five out of 10 long-term survivors have not developed neuroendocrine deficits.

CONCLUSIONS

Re-irradiation with CSI is a safe and effective treatment for children with locally recurrent ependymoma and improves disease control compared with focal re-irradiation, with the benefit most apparent for those with infratentorial primary tumors.

Intracranial ependymomas: molecular insights and translation to treatment

Ependymomas are primary central nervous system tumors (CNS), arising within the posterior fossa and supratentorial regions of the brain, and in the spine. Over the last decade, research has resulted in substantial insights into the molecular characteristics of ependymomas, and significant advances have been made in the establishment of a molecular classification system. Ependymomas both within and between the three CNS regions in which they arise, have been shown to contain distinct genetic, epigenetic and cytogenic aberrations, with at least three molecularly distinct subgroups identified within each region. However, these advances in molecular characterization have yet to be translated into clinical practice, with the standard treatment for ependymoma patients largely unchanged. This review summarizes the advances made in the molecular characterization of intracranial ependymomas, outlines the progress made in establishing preclinical models and proposes strategies for moving toward subgroup-specific preclinical investigations and treatment.

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.

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.

Management of Ependymoma in Children, Adolescents and Young Adults

Paediatric ependymomas are rare, malignant tumours arising throughout the central nervous system, but most frequently (in children) the posterior fossa. The standard of care for localised disease is gross total resection and focal radiotherapy, resulting in overall survival rates of up to 85%. Despite improvements in survival, treatment remains challenging, with persistently high rates of (rarely curable) relapse alongside risks of significant tumour and treatment-related toxicity. Systemic therapy is currently used to delay radiotherapy in very young children and in the management of metastatic or recurrent disease. Its use in the adjuvant setting is the subject of ongoing studies. Current research efforts are aimed at eliciting a better understanding of molecular biology, correlating this with tumour behaviour and defining targets for potential new agents. Prognosis seems to be related to the extent of surgical resection and the age at presentation. This article reviews clinical aspects of ependymoma management in children and young people.

Pediatric ependymoma: current treatment and newer therapeutic insights

Advances in genomic, transcriptomic and epigenomic profiling now identifies pediatric ependymoma as a defined biological entity. Molecular interrogation has segregated these tumors into distinct biological subtypes based on anatomical location, age and clinical outcome, which now defines the need to tailor therapy even for histologically similar tumors. These findings now provide reasons for a paradigm shift in therapy, which should profile future clinical trials focused on targeted therapeutic strategies and risk-based treatment. The need to diagnose and differentiate the aggressive variants, which include the posterior fossa group A and the supratentorial RELA fusion subtypes, is imperative to escalate therapy and improve survival.

EANO guidelines for the diagnosis and treatment of ependymal tumors

Ependymal tumors are rare CNS tumors and may occur at any age, but their proportion among primary brain tumors is highest in children and young adults. Thus, the level of evidence of diagnostic and therapeutic interventions is higher in the pediatric compared with the adult patient population.The diagnosis and disease staging is performed by craniospinal MRI. Tumor classification is achieved by histological and molecular diagnostic assessment of tissue specimens according to the World Health Organization (WHO) classification 2016. Surgery is the crucial initial treatment in both children and adults. In pediatric patients with intracranial ependymomas of WHO grades II or III, surgery is followed by local radiotherapy regardless of residual tumor volume. In adults, radiotherapy is employed in patients with anaplastic ependymoma WHO grade III, and in case of incomplete resection of WHO grade II ependymoma. Chemotherapy alone is reserved for young children <12 months and for adults with recurrent disease when further surgery and irradiation are no longer feasible. A gross total resection is the mainstay of treatment in spinal ependymomas, and radiotherapy is reserved for incompletely resected tumors. Nine subgroups of ependymal tumors across different anatomical compartments (supratentorial, posterior fossa, spinal) and patient ages have been identified with distinct genetic and epigenetic alterations, and with distinct outcomes. These findings may lead to more precise diagnostic and prognostic assessments, molecular subgroup-adapted therapies, and eventually new recommendations pending validation in prospective studies.

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.

New developments in immunotherapy for pediatric solid tumors

PURPOSE OF REVIEW

Building upon preclinical advances, we are uncovering immunotherapy strategies that are translating into improved outcomes in tumor subsets. Advanced pediatric solid tumors carry poor prognoses and resultant robust efforts to apply immunotherapy advances to pediatric solid tumors are in progress. Here, we discuss recent developments in the field using mAb and mAb-based therapies including checkpoint blockade and chimeric antigen receptors (CARs).

RECENT FINDINGS

The pediatric solid tumor mAb experience targeting the diganglioside, GD2, for patients with neuroblastoma has been the most compelling to date. GD2 and alternative antigen-specific mAbs are now being incorporated into antibody-drug conjugates, bispecific antibodies and CARs for treatment of solid tumors. CARs in pediatric solid tumors have not yet achieved comparative responses to the hematologic CAR experience; however, novel strategies such as bispecific targeting, intratumoral administration and improved understanding of T-cell biology may yield enhanced CAR-efficacy. Therapeutic effect using single-agent checkpoint blocking antibodies in pediatric solid tumors also remains limited to date. Combinatorial strategies continue to hold promise and the clinical effect in tumor subsets with high antigenic burden is being explored.

SUMMARY

Pediatric immunotherapy remains at early stages of translation, yet we anticipate that with advanced technology, we will achieve widespread, efficacious use of immunotherapy for pediatric solid tumors.

Outcomes After Reirradiation for Recurrent Pediatric Intracranial Ependymoma

PURPOSE

To determine the long-term outcomes and the optimal dose and volume for reirradiation of recurrent pediatric ependymoma.

METHODS AND MATERIALS

Patients with recurrent ependymoma treated with a second course of fractionated radiation therapy (RT2) were reviewed retrospectively. Eligible patients had localized, intracranial ependymoma at initial diagnosis that was treated with focal radiation (RT1) without craniospinal irradiation (CSI) and were aged ≤21 years at the time of RT2. The median doses of RT1, focal RT2, and CSI-RT2 were 59.4, 54, and 39.6 Gy, respectively. The primary endpoint, overall survival (OS), was measured from the first day of RT2.

RESULTS

We included 101 patients in the study. The median interval between RT1 and RT2 was 26.8 months (interquartile range, 18.0-43.1). The median durations of OS and freedom from progression (FFP) were 75.1 and 27.3 months, respectively. Male sex and anaplastic histology at recurrence were associated with decreased OS and FFP on multivariate analysis. Distant-only failure treated with CSI-RT2 was independently associated with improved OS compared with individuals with local failure treated with focal RT2 (hazard ratio 0.37; 95% confidence interval 0.16-0.87). Among individuals experiencing any distant failure after RT1, gain of chromosome 1q was adversely associated with poorer OS (hazard ratio 3.5; 95% confidence interval 1.1-10.6). No distant-only failures were observed in individuals with RT1 local failure who received CSI-RT2 (n=10). The 10-year cumulative incidence of grade ≥3 radiation necrosis after RT2 was 7.9%.

CONCLUSIONS

Reirradiation for relapsed pediatric ependymoma was well tolerated by most patients and resulted in long-term survival in a subset of patients. The best results were observed in patients who experienced distant-only failure after RT1 and were treated with CSI as part of RT2, without anaplasia at recurrence. The option of reirradiation should be discussed with patients who develop recurrent ependymoma.

Pediatric Ependymoma

Over the past 150 years since Virchow's initial characterization of ependymoma, incredible efforts have been made in the classification of these tumors and in the care of pediatric patients with this disease. While the advent of modern neurosurgery and the optimization of radiation have provided significant gains, a more complex but incomplete picture of pediatric ependymomas has begun to form through a combination of international collaborations and detailed genetic and histologic characterizations. This review includes and synthesizes the clinical understanding of pediatric ependymoma and their developing molecular insight into what is truly a family of malignancies in which distinct members require different surgical approaches, radiation plans, and targeted therapies.

Reirradiation of Pediatric Tumors Using Hypofractionated Stereotactic Radiotherapy

BACKGROUND

This study aimed to evaluate the efficacy and safety of hypofractionated stereotactic radiotherapy for reirradiation of recurrent pediatric tumors.

METHODS AND MATERIALS

The study included 23 pediatric patients who were reirradiated using hypofractionated stereotactic radiotherapy in the radiation oncology department between January 2008 and November 2013. In total, 33 tumors were treated-27 (82%) cranial and 6 (18%) extracranial. Hypofractionated stereotactic radiotherapy was administered due to recurrent disease in 31 (94%) tumors and residual disease in 2 (6%) tumors. The median total dose was 25 Gy (range: 15-40 Gy), and the median follow-up was 20 months (range: 2-68 months).

RESULTS

The 1-year and 2-year local control rates in the entire study population were 42% and 31%, respectively. The median local control time was 11 months (range: 0-54 months) following hypofractionated stereotactic radiotherapy. The patients with tumor response after hypofractionated stereotactic radiotherapy had significantly longer local control than the patients with post-hypofractionated stereotactic radiotherapy tumor progression (21 vs 3 months, P < .001). Tumor volume <1.58 cm³ was correlated (not significantly) with better local control (23 vs 7 months, P = .064).

CONCLUSION

Reirradiation of pediatric tumors using hypofractionated stereotactic radiotherapy is a safe and effective therapeutic approach. This treatment modality should be considered as a treatment option in selected pediatric patients.

Advances in Management of Pediatric Ependymomas

Ependymomas are a heterogeneous group of neuroepithelial tumors of children and adults. In pediatric cases, the standard of care has long consisted of neurosurgical resection to the greatest extent acceptable followed by adjuvant involved field irradiation. Complete macroscopic surgical resection has remained the only consistent clinical variable known to improve survival. Adjuvant chemotherapy has yet to predictably affect outcome, possibly due to the molecular heterogeneity of histologically similar tumors. The administration of chemotherapy subsequently remains limited to clinical trials. However, recent comprehensive genomic, transcriptomic, and epigenetic interrogations of ependymomas have uncovered unique molecular characteristics and subtypes that correlated with clinical features such as age, neuroanatomical location, and prognosis. These findings represent a potential paradigm shift and provide a biologic rationale for targeted therapeutic strategies and risk-adapted administration of conventional treatment modalities. In this review, we focus on intracranial WHO grade II and III ependymoma of children and discuss conventional management strategies, followed by recent biologic findings and novel therapeutics currently under investigation.

Pediatric Brain Tumors: Current Knowledge and Therapeutic Opportunities

Great progress has been made in many areas of pediatric oncology. However, tumors of the central nervous system (CNS) remain a significant challenge. A recent explosion of data has led to an opportunity to understand better the molecular basis of these diseases and is already providing a foundation for the pursuit of rationally chosen therapeutics targeting relevant molecular pathways. The molecular biology of pediatric brain tumors is shifting from a singular focus on basic scientific discovery to a platform upon which insights are being translated into therapies.

Translational Pharmacokinetic-Pharmacodynamic Modeling and Simulation: Optimizing 5-Fluorouracil Dosing in Children With Pediatric Ependymoma

We previously investigated novel therapies for pediatric ependymoma and found 5‐fluorouracil (5‐FU) i.v. bolus increased survival in a representative mouse model. However, without a quantitative framework to derive clinical dosing recommendations, we devised a translational pharmacokinetic‐pharmacodynamic (PK‐PD) modeling and simulation approach. Results from our preclinical PK‐PD model suggested tumor concentrations exceeded the 1‐hour target exposure (in vitro IC₉₀), leading to tumor growth delay and increased survival. Using an adult population PK model, we scaled our preclinical PK‐PD model to children. To select a 5‐FU dosage for our clinical trial in children with ependymoma, we simulated various 5‐FU dosages for tumor exposures and tumor growth inhibition, as well as considering tolerability to bolus 5‐FU administration. We developed a pediatric population PK model of bolus 5‐FU and simulated tumor exposures for our patients. Simulations for tumor concentrations indicated that all patients would be above the 1‐hour target exposure for antitumor effect.

Temozolomide Treatment for Pediatric Refractory Anaplastic Ependymoma with Low MGMT Protein Expression

The benefit of postoperative chemotherapy for anaplastic ependymoma remains unknown. We report two pediatric patients with refractory anaplastic ependymoma treated with temozolomide (TMZ). We did not detect O(6) -methylguanine-DNA methyltransferase (MGMT) promoter methylation in tumor samples; however, MGMT protein expression was low. With TMZ treatment, one patient had a 7-month complete remission; the other, stable disease for 15 months. Three other patients did not respond to TMZ; two had high and one low MGMT expression, and two showed no MGMT promoter methylation. These findings suggest that TMZ may be effective for pediatric refractory anaplastic ependymoma with low MGMT protein expression.

Temozolomide as salvage treatment for recurrent intracranial ependymomas of the adult: a retrospective study

BACKGROUND

Few data are available on temozolomide (TMZ) in ependymomas.We investigated the response, survival, and correlation with MGMT promoter methylation in a cohort of patients with adult intracranial ependymoma receiving TMZ as salvage therapy after failure of surgery and radiotherapy.

PATIENTS AND METHODS

We retrieved clinical information from the institutional database and follow-up visits, and response to TMZ on MRI was evaluated according to the MacDonald criteria.

RESULTS

Eighteen patients (median age, 42 y), with either WHO grade III (10) or grade II (8) ependymoma were evaluable. Tumor location at diagnosis was supratentorial in 11 patients and infratentorial in 7. Progression before TMZ was local in 11 patients, local and spinal in 6 patients, and spinal only in one patient. A median of 8 cycles of TMZ (1-24) was administered. Response to TMZ consisted of complete response (CR) in one (5%) patient, partial response (PR) in 3 (17%) patients, stable disease (SD) in 7 (39%) patients, and progressive disease (PD) in 7 (39%) patients. Maximum response occurred after 3, 10, 14, and 15 cycles, respectively, with neurological improvement in 2 patients. All 4 responding patients were chemotherapy naïve. Both anaplastic (2) and grade II (2) tumors responded. Median progression-free survival and overall survival were 9.69 months (95% CI, 3.22-30.98) and 30.55 months (95% CI, 12.85-52.17), respectively. MGMT methylation was available in 11 patients and was not correlated with response or outcome.

CONCLUSION

TMZ has a role in recurrent chemo-naïve adult patients with intracranial ependymoma, regardless of tumor grade and MGMT methylation. We suggest that, after failure of surgery and radiotherapy, TMZ should be considered as a possible first-line treatment for recurrent ependymoma.

An open-label, two-stage, phase II study of bevacizumab and lapatinib in children with recurrent or refractory ependymoma: a collaborative ependymoma research network study (CERN)

Co-expression of ERBB2 and ERBB4, reported in 75% of pediatric ependymomas, correlates with worse overall survival. Lapatinib, a selective ERBB1 and ERBB2 inhibitor has produced prolonged disease stabilization in patients with ependymoma in a phase I study. Bevacizumab exposure in ependymoma xenografts leads to ablation of tumor self-renewing cells, arresting growth. Thus, we conducted an open-label, phase II study of bevacizumab and lapatinib in children with recurrent ependymomas. Patients ≤ 21 years of age with recurrent ependymoma received lapatinib orally twice daily (900 mg/m(2)/dose to the first 10 patients, and then 700 mg/m(2)/dose) and bevacizumab 10 mg/kg intravenously on days 1 and 15 of a 28-day course. Lapatinib serum trough levels were analyzed prior to each course. Total and phosphorylated VEGFR2 expression was measured in peripheral blood mononuclear cells (PBMCs) before doses 1 and 2 of bevacizumab and 24-48 h following dose 2 of bevacizumab. Twenty-four patients with a median age of 10 years (range 2-21 years) were enrolled; 22 were eligible and 20 evaluable for response. Thirteen had anaplastic ependymoma. There were no objective responses; 4 patients had stable disease for ≥ 4 courses (range 4-14). Grade 3 toxicities included rash, elevated ALT, and diarrhea. Grade 4 toxicities included peri-tracheostomy hemorrhage (n = 1) and elevated creatinine phosphokinase (n = 1). The median lapatinib pre-dose trough concentration was 3.72 µM. Although the combination of bevacizumab and lapatinib was well tolerated in children with recurrent ependymoma, it proved ineffective.

Paediatric intracranial anaplastic ependymoma: the role of multiple surgical resections for disease relapse in maintaining quality of life and prolonged survival

INTRODUCTION

Ependymoma is the third most common intracranial glioma in children. The treatment of choice for these tumours remains gross total resection followed by radiotherapy. There are two principal histological subtypes, namely classic (∼70%) and anaplastic (∼30%) ependymoma.

CASE

We present the case of a 12-year-old girl with an anaplastic ependymoma of the left temporal lobe. She underwent initial image-guided resection following biopsy. A postoperative MRI showed a macroscopic resection. She subsequently relapsed and indeed had 11 local and distant relapses managed by 12 separate craniotomies and tumour resection, 4 courses of radiotherapy and chemotherapy.

CONCLUSION

For patients with multiple relapses, surgery should be considered primarily to re-resect any symptomatic lesion. This case demonstrates that multiple tumour resections can be undertaken with limited morbidity for the patient and with maintenance of quality of life. Repeated focal irradiation can also be used to control the disease with limited morbidity.

Infratentorial ependymomas--a study of the centre in Katowice

The aim of the study was to assess the correlation of the results of the treatment of infratentorial ependymomas with the degree of resection and histopathological diagnosis. The study was conducted on a group of 19 patients, 13 boys and 6 girls aged 3 months to 16 years, with infratentorial ependymoma treated at the Department of Paediatric Neurosurgery of the Medical University of Silesia in Katowice from January 2000 until December 2008. The most significant factor having an impact on overall survival and progression-free survival was totality of tumour resection. There has been no statistically significant influence of the histopathological type of ependymoma on the result of treatment. The tendency to report better results of treatment of non-anaplastic ependymoma seems to derive from a statistically higher frequency of total removal of tumours of this type.

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.