Relapsed intracranial ependymoma in children in the UK: Patterns of relapse, survival and therapeutic outcome

Intracranial ependymoma with extremely rare extraneural metastasis

Ependymomas account for 1-8% of overall brain tumors. They are most common at the age of 3-4 years. Their metastasis is very rare, and extraneural metastasis is even more unusual. In this report, the ependymoma localized in the posterior fossa with metastasis into femoral diaphysis in a 27-year-old male patient, who was treated in 2001, is presented. As we did not have any other cases of patients having a brain and spinal tumor with extraneural metastases even after 21 years, until 2022, this case was found worthy of being presented. When the literature was examined, it was observed that there is still no standard treatment after surgery for ependymomas and their metastasis. Due to their rarity, the general treatment of extraneural metastasis of ependymomas is also under discussion. It is recommended that clinicians consider admitting patients with rare or hard-to-treat tumors to ongoing clinical trials.

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.

Proton Beam Therapy in the Reirradiation Setting of Brain and Base of Skull Tumour Recurrences

The therapeutic management of local tumour recurrence after a first course of radical radiotherapy is always complex. Surgery and reirradiation carry increased morbidity due to radiation-induced tissue changes. Proton beam therapy (PBT) might be advantageous in the reirradiation setting, thanks to its distinct physical characteristics. Here we systematically reviewed the use of PBT in the management of recurrent central nervous system (CNS) and base of skull (BoS) tumours, as published in the literature. The research question was framed following the Population, Intervention, Comparison and Outcomes (PICO) criteria: the population of the study was cancer patients with local disease recurrence in the CNS or BoS; the intervention was radiation treatment with PBT; the outcomes of the study focused on the clinical outcomes of PBT in the reirradiation setting of local tumour recurrences of the CNS or BoS. The identification stage resulted in 222 records in Embase and 79 in Medline as of March 2023. Sixty-eight duplicates were excluded at this stage and 56 were excluded after screening as not relevant, not in English or not full-text articles. Twelve full-text articles were included in the review and are presented according to the site of disease, namely BoS, brain or both brain and BoS. This review showed that reirradiation of brain/BoS tumour recurrences with PBT can provide good local control with acceptable toxicity rates. However, reirradiation of tumour recurrences in the CNS or BoS setting needs to consider several factors that can increase the risk of toxicities. Therefore, patient selection is crucial. Randomised evidence is needed to select the best radiation modality in this group of patients.

Patterns of Extraneural Metastases in Children With Ependymoma

Ependymomas account for 10% of all malignant pediatric central nervous system tumors. Standard therapy includes maximal safe surgical resection, followed by focal radiation. Despite the aggressive therapy, progression-free survival is poor. Most ependymoma relapses occur locally at the original tumor site. Extraneural presentations of ependymoma are extremely rare, and no standard of care treatment exists. We present a single-institution case series of 3 patients who experienced extraneural relapses of supratentorial ependymoma and describe their treatment and outcome. These cases of extraneural relapse highlight the possible modes of extraneural spread, including hematogenous, lymphatic, and microscopic seeding through surgical drains and shunts. In addition, they illustrate the increase in histologic grade and mutational burden that may occur at the time of relapse. These cases illustrate the role of aggressive, individualized treatment interventions using a combination of surgery, radiation, and chemotherapy.

Extra-Neural Metastases of Late Recurrent Myxopapillary Ependymoma to Left Lumbar Paravertebral Muscles: Case Report and Review of the Literature

Ependymomas are commonly classified as low-grade tumors, although they may harbor a malignant behavior characterized by distant neural dissemination and spinal drop metastasis. Extra-CNS ependymoma metastases are extremely rare and only few cases have been reported in the lung, lymph nodes, pleura, mediastinum, liver, bone, and diaphragmatic, abdominal, and pelvic muscles. A review of the literature yielded 14 other case reports metastasizing outside the central nervous system, but to our knowledge, no studies describe metastasis in the paravertebral muscles. Herein, we report the case of a 39-year-old patient with a paraspinal muscles metastasis from a myxopapillary ependymoma. The neoplasm was surgically excised and histologically and molecularly analyzed. Both the analyses were consistent with the diagnosis of muscle metastases of myxopapillary ependymoma. The here-presented case report is first case in the literature of a paraspinal muscles metastasis of myxopapillary ependymoma.

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.

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.

Treatment and outcome of intracranial ependymoma after first relapse in AIEOP 2 nd protocol

BACKGROUND

More than 40% of patients with intracranial ependymoma need a salvage treatment within 5 years after diagnosis, and no standard treatment is available as yet. We report the outcome after first relapse of 64 patients treated within the 2 nd AIEOP protocol.

METHODS

We considered relapse sites and treatments ,i.e. various combinations of complete/incomplete surgery, if followed by standard or hypo-fractionated radiation(RT) ± chemotherapy(CT). Molecular analyses were available for 38/64 samples obtained at first diagnosis. Of the 64 cases, 55 were suitable for subsequent analyses.

RESULTS

The median follow-up was 147 months after diagnosis, 84 after first relapse, 5-year EFS/OS were 26.2%/30.8% (median EFS/OS 13/32 months) after relapse. For patients with a local relapse(LR), the 5-year cumulative incidence of second LRs was 51.6%, with a 5-year event-specific probability of being LR-free of 40.0%. Tumor site/grade, need for shunting, age above/below 3 years, molecular subgroup at diagnosis, had no influence on outcomes. Due to variation in the RT dose/fractionation used and the subgroup sizes it was not possible to assess the impact of the different RT modalities. Multivariable analyses identified completion of surgery, absence of symptoms at relapse, and female sex as prognostically favorable. Tumors with a 1q gain carried a higher cumulative incidence of dissemination after first relapse.

CONCLUSIONS

Survival after recurrence was significantly influenced by symptoms and completeness of surgery. Only a homogeneous protocol with well posed, randomized questions could clarify the numerous issues, orient salvage treatment and ameliorate prognosis for this group of patients.

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%).

Childhood Cancer: Occurrence, Treatment and Risk of Second Primary Malignancies

Cancer represents the leading cause of disease-related death and treatment-associated morbidity in children with an increasing trend in recent decades worldwide. Nevertheless, the 5-year survival of childhood cancer patients has been raised impressively to more than 80% during the past decades, primarily attributed to improved diagnostic technologies and multiagent cytotoxic regimens. This strong benefit of more efficient tumor control and prolonged survival is compromised by an increased risk of adverse and fatal late sequelae. Long-term survivors of pediatric tumors are at the utmost risk for non-carcinogenic late effects such as cardiomyopathies, neurotoxicity, or pneumopathies, as well as the development of secondary primary malignancies as the most detrimental consequence of genotoxic chemo- and radiotherapy. Promising approaches to reducing the risk of adverse late effects in childhood cancer survivors include high precision irradiation techniques like proton radiotherapy or non-genotoxic targeted therapies and immune-based treatments. However, to date, these therapies are rarely used to treat pediatric cancer patients and survival rates, as well as incidences of late effects, have changed little over the past two decades in this population. Here we provide an overview of the epidemiology and etiology of childhood cancers, current developments for their treatment, and therapy-related adverse late health consequences with a special focus on second primary malignancies.

Sequential Orbitrap Secondary Ion Mass Spectrometry and Liquid Extraction Surface Analysis-Tandem Mass Spectrometry-Based Metabolomics for Prediction of Brain Tumor Relapse from Sample-Limited Primary Tissue Archives

We present here a novel surface mass spectrometry strategy to perform untargeted metabolite profiling of formalin-fixed paraffin-embedded pediatric ependymoma archives. Sequential Orbitrap secondary ion mass spectrometry (3D OrbiSIMS) and liquid extraction surface analysis-tandem mass spectrometry (LESA-MS/MS) permitted the detection of 887 metabolites (163 chemical classes) from pediatric ependymoma tumor tissue microarrays (diameter: <1 mm; thickness: 4 μm). From these 163 classes, 60 classes were detected with both techniques, whilst LESA-MS/MS and 3D OrbiSIMS individually allowed the detection of another 83 and 20 unique metabolite classes, respectively. Through data fusion and multivariate analysis, we were able to identify key metabolites and corresponding pathways predictive of tumor relapse, which were retrospectively confirmed by gene expression analysis with publicly available data. Altogether, this sequential mass spectrometry strategy has shown to be a versatile tool to perform high-throughput metabolite profiling on sample-limited tissue archives.

Radiosurgery, reirradiation, and brachytherapy

Radiosurgery and brachytherapy are potentially useful treatment techniques that are sparingly applied in pediatric oncology. They are often used in the setting of reirradiation for recurrent or metastatic tumors. Reirradiation in children with recurrent tumors is complicated by the tolerance of critical organs and the potential risks for overall long-term dose-dependent complications. We review the current literature available in support of reirradiation and the use of radiosurgery and brachytherapy in pediatric patients.

BLBP Is Both a Marker for Poor Prognosis and a Potential Therapeutic Target in Paediatric Ependymoma

Paediatric ependymomas are aggressive, treatment-resistant tumours with a tendency towards relapse, consistent with a sub-population of therapy-resistant cancer stem cells. These cells are believed to derive from brain lipid binding protein (BLBP)-expressing radial glia, hence we proposed that BLBP may be a marker for ependymoma therapy resistance. BLBP protein expression correlated with reduced overall survival (OS) in patients from two trials (CNS9204, a chemotherapy-led infant trial-5 y OS 45% vs. 80%, p = 0.011-and CNS9904, a radiotherapy-led trial-OS 38% vs. 85%, p = 0.002). All ependymoma cell lines examined by qRT-PCR expressed BLBP, with expression elevated in stem cell-enriched neurospheres. Modulation of BLBP function in 2D and 3D assays, using either peroxisome proliferator activated receptor (PPAR) antagonists or BLBP's fatty acid substrate docosahexaneoic acid (DHA), potentiated chemotherapy response and reduced cell migration and invasion in ependymoma cell lines. BLBP is therefore an independent predictor of poor survival in paediatric ependymoma, and treatment with PPAR antagonists or DHA may represent effective novel therapies, preventing chemotherapy resistance and invasion in paediatric ependymoma patients.

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.

Survival after therapy for pediatric ependymoma in a tertiary care center in Saudi Arabia

BACKGROUND

There is limited data from Saudi Arabia on the demographic characteristics, outcomes and effectiveness of different treatment modalities in children with intracranial ependymoma.

OBJECTIVE

Study the characteristics of pediatric ependymoma and outcomes of treatment modalities in Saudi Arabia.

DESIGN

Retrospective.

SETTING

Tertiary care center.

PATIENTS AND METHODS

Children with intracranial ependymoma who were younger than 14 years of age and treated between 2006 and 2015 were included in the study. Patients with prior radiation, chemo-therapy, or surgical resection at other centers were excluded.

MAIN OUTCOME MEASURES

Kaplan-Meier survival curves were used to estimate the event-free (EFS) and overall survival (OS) rates of the patients.

SAMPLE SIZE

22.

RESULTS

Of the 22 children, 4 (18.2%) were less than three years old. All intracranial ependymomas had upfront surgical resection of the primary tumor. Gross total resection was achievable in 9 (42.9%) cases and subtotal resection in another 9 (42.9%). Near-total resection was done in 3 (14.3%) cases. Median time from surgery to start of radiotherapy was 62 days. RT was given to 17 (77.3%) patients. Both mean and median RT dose was 55.8 Gy. Only 5 (22.7%) of the children received chemotherapy. The median duration of follow-up was 5.38 years and the median time for EFS was 2.27 years. The cumulative OS rate of the study was 44.5%. The cumulative EFS survival rate of the study was 18.6%. Among demographic, pathological, radiological features, none had a statistically significant effect on the survival.

CONCLUSIONS

The outcomes are comparable to those reported by international investigators for similar populations. Further improvements can be achieved by avoiding delays in radiation therapy and adding molecular staging.

LIMITATIONS

The limited number of cases, retrospective nature, lack of molecular biology and size of the tumors.

CONFLICT OF INTEREST

None.

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.

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.

Extent of re-excision, sequence/timing of salvage re-irradiation, and disease-free interval impact upon clinical outcomes in recurrent/progressive ependymoma

PURPOSE

To report clinical outcomes of salvage re-irradiation (re-RT) in recurrent/progressive ependymoma.

METHODS

Medical records of patients treated with curative-intent re-RT as multi-modality management for recurrent/progressive ependymoma were analyzed retrospectively. The linear-quadratic model was used to provide estimates of biologically effective dose (BED) of irradiation using an α/β value of 2 for late CNS toxicity for each course of irradiation and summated to derive cumulative BED without correcting for the assumed recovery.

RESULTS

A total of 55 patients (median age 10 years at index diagnosis) treated with curative-intent re-RT between 2010 and 2018 were included. Median time to first recurrence was 29 months with an inter-quartile range (IQR) of 16-64 months. Majority (n = 46, 84%) of patients underwent surgical re-excision of recurrent disease. Median interval from first course of irradiation (RT1) to second course (RT2) was 35 months (IQR = 26-66 months) with a median re-RT dose of 54 Gy in 30 fractions (range 40-60 Gy), resulting in median cumulative equivalent dose in 2 Gy fraction (EQD2) of 106.2 Gy (range 92.4-117.6 Gy). Volume of re-RT was based on location and pattern of relapse, comprising uni-focal (n = 49, 89%), multi-focal (n = 3, 5.5%), or craniospinal irradiation (CSI) in 3 (5.5%) patients respectively. Thirty-six (66%) patients received platinum-based salvage chemotherapy either before or after RT2. At a median follow up of 37 months (range 6-80 months), the Kaplan-Meier estimates of 3-year progression-free survival (PFS) and overall survival (OS) for the entire study cohort were 40% and 51% respectively. Gross total resection at recurrence; early salvage re-RT (prior to chemotherapy, if any); and longer (> 2 years) disease-free interval (DFI) were associated with better survival outcomes. Salvage re-RT was generally well tolerated with only 3 (5.5%) patients developing symptomatic radiation necrosis necessitating corticosteroids.

CONCLUSION

Extent of re-excision, sequence/timing of re-RT, and DFI impact upon outcomes in curative-intent, multi-modality salvage therapy for recurrent ependymoma.

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.

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.

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.

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.

Low-dose Actinomycin-D treatment re-establishes the tumoursuppressive function of P53 in RELA-positive ependymoma

Ependymomas in children can arise throughout all compartments of the central nervous system (CNS). Highly malignant paediatric ependymoma subtypes are Group A tumours of the posterior fossa (PF-EPN-A) and RELA-fusion positive (ST-EPN-RELA) tumours in the supratentorial compartment. It was repeatedly reported in smaller series that accumulation of p53 is frequently observed in ependymomas and that immunohistochemical staining correlates with poor clinical outcome, while TP53 mutations are rare. Our TP53 mutation analysis of 130 primary ependymomas identified a mutation rate of only 3%. Immunohistochemical analysis of 398 ependymomas confirmed previous results correlating the accumulation of p53 with inferior outcome. Among the p53-positive ependymomas, the vast majority exhibited a RELA fusion leading to the hypothesis that p53 inactivation might be linked to RELA positivity.

In order to assess the potential of p53 reactivation through MDM2 inhibition in ependymoma, we evaluated the effects of Actinomycin-D and Nutlin-3 treatment in two preclinical ependymoma models representing the high-risk subtypes PF-EPN-A and ST-EPN-RELA. The IC-50 of the agent as determined by metabolic activity assays was in the lower nano-molar range (0.2–0.7 nM). Transcriptome analyses of high-dose (100 nM), low-dose (5 nM) and non-treated cells revealed re-expression of p53 dependent genes including p53 upregulated modulator of apoptosis (PUMA) after low-dose treatment. At the protein level, we validated the Actinomycin-D induced upregulation of PUMA, and of p53 interaction partners MDM2 and p21. Proapoptotic effects of low-dose application of the agent were confirmed by flow cytometry. Thus, Actinomycin-D could constitute a promising therapeutic option for ST-EPN-RELA ependymoma patients, whose tumours frequently exhibit p53 inactivation.

Impact of radiation therapy and extent of resection for ependymoma in young children: A population-based study

BACKGROUND

Young children with posterior fossa ependymoma (PF-EPN) have a worse prognosis than older children, and they have a unique molecular profile (PF-EPN-A subtype). Alternative treatment strategies are often used in these young patients, and their prognostic factors are less clear.

METHODS

We characterized the prognostic factors and treatment outcomes of 482 patients between ages 0 and 3 years with the diagnosis of ependymoma identified from the Surveillance, Epidemiology, and End Results registry (1973-2013).

RESULTS

Radiation therapy (RT) was delivered to 52.3% of patients, and gross total resection (GTR) was performed in 51.0% of patients. Overall survival (OS) at 10 years was 48.4% with median follow-up of 3.3 years. WHO grade was not predictive of OS. Extent of resection was significant for survival; the 10-year OS with GTR was 61.0%, and with subtotal resection (STR) and biopsy was 38.2% and 35.0%, respectively (P < 0.001). RT significantly benefitted OS for both grades II and III. The 10-year OS for grade II was 50.5% with RT and 43.4% without (P = 0.030); 10-year OS for grade III was 66.0% with RT and 40.0% without (P = 0.002). Multivariate analysis showed significantly improved OS with RT (hazard ratio [HR] 0.601, 95% CI: 0.439-0.820, P = 0.001) and GTR (HR 0.471, 95% CI: 0.328-0.677, P < 0.0001).

CONCLUSIONS

Ependymoma outcomes in patients within 0-3 years of age significantly improved with RT and GTR. Histopathologic grading of ependymoma demonstrated no prognostic significance. Given the poor OS for this population and unique genetic profile, future prospective studies with molecular-based stratification should be performed to evaluate additional prognostic factors.

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.

Molecular mechanisms and therapeutic targets in pediatric brain tumors

Brain tumors are among the leading causes of cancer-related deaths in children. Although surgery, aggressive radiation, and chemotherapy have improved outcomes, many patients still die of their disease. Moreover, those who survive often suffer devastating long-term side effects from the therapies. A greater understanding of the molecular underpinnings of these diseases will drive the development of new therapeutic approaches. Advances in genomics and epigenomics have provided unprecedented insight into the molecular diversity of these diseases and, in several cases, have revealed key genes and signaling pathways that drive tumor growth. These not only serve as potential therapeutic targets but also have facilitated the creation of animal models that faithfully recapitulate the human disease for preclinical studies. In this Review, we discuss recent progress in understanding the molecular basis of the three most common malignant pediatric brain tumors-medulloblastoma, ependymoma, and high-grade glioma-and the implications for development of safer and more effective 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.

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.

Study of stem cell marker nestin and its correlation with vascular endothelial growth factor and microvascular density in ependymomas

BACKGROUND

Ependymomas are relatively rare glial tumours, whose pathogenesis is not well elucidated. They are enigmatic tumours that show site-specific differences in their biological behaviour. Recent studies have hypothesized that ependymoma cancer stem cells (CSCs) are derived from radial glia and express stem cell markers such as nestin, which is associated with a poor prognosis. CSCs reside in 'vascular niches', where endothelial cells and molecular signals like vascular endothelial growth factor (VEGF) play an important role in their survival. Studies analysing VEGF expression in ependymomas showed that ependymal vascular proliferation is less sensitive to induction by VEGF, questioning the possible beneficial effect of anti-VEGF therapy in ependymomas. We aimed to study nestin and VEGF immunoexpression in ependymomas, correlate them with clinicopathological parameters and reveal a role for VEGF in ependymomas that extends beyond the context of tumour angiogenesis.

METHODS

We analysed 126 cases of ependymomas of different grades and locations for nestin and VEGF immunoexpression. Endothelial cells were labelled with CD34. Vascular patterns and microvascular density was determined.

RESULTS

Nestin and VEGF expression in tumour cells were more frequent in supratentorial tumours [89% (33/37) and 65% (24/37) respectively], and were associated with a significantly poor progression-free survival (PFS). VEGF expression did not reveal any correlation with necrosis or bizarre vascular patterns.

CONCLUSIONS

Supratentorial location is an independent predictor of a poor PFS. Significant coexpression of nestin and VEGF suggests that latter possibly augments stem cell survival. Thus, anti-VEGF therapy may be a good option in future for nestin immunopositive ependymomas.

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.

A retrospective analysis of recurrent intracranial ependymoma

BACKGROUND

Recurrence occurs in almost 50% of patients with intracranial ependymoma, and their outcome following recurrence is poor.

METHODS

We retrospectively reviewed the medical records of 22 patients with intracranial ependymoma and subsequent relapse(s) (59 recurrences) treated at Children's Hospital Los Angeles or New York University between January 1997 and December 2012.

RESULTS

Median duration of follow-up was 52 months (7-171 months). Median age at initial diagnosis was 4 years (0.3-19 years) with 8 patients younger than 3 years at presentation. Eleven patients had anaplastic and 11 cellular pathologies. Eighteen patients had infratentorial tumors at diagnosis and 3 (all infratentorial) had metastatic spinal cord involvement at presentation. Cerebrospinal fluid involvement was not identified at diagnosis or relapse. Median time to first recurrence was 16 months (1.3 to 115 months). The number of recurrences in each patient ranged from 1 to 9 (median = 2). Thirty-seven recurrences (63%) were detected asymptomatically by surveillance imaging. Fifteen recurrences (26%) arose outside the initial tumor site. Recurrences were treated by surgical resection (45), with irradiation (30), and with various oral chemotherapies (23) with (7) or without (16) conventional chemotherapy. The 5 and 10 year overall survival rates from first recurrence were 0.37 ± 0.14 and 0.25 ± 0.14.

CONCLUSION

Prolonged (5-10 year) survival from first relapse was noted in over one-quarter of our patients. It remains unclear whether early radiographic diagnosis, differing treatment modalities beyond radical surgical resection or possibly unrecognized biological differences contributed towards this prolonged survival.

Extraneural metastasis of an ependymoma: a rare occurrence

Extraneural metastases of ependymoma are very rare, and have been reported in the lungs, lymph nodes, pleura, mediastinum, liver, diaphragmatic muscle, and bone. We describe the radiological findings of pathologically proven lung metastases from an anaplastic ependymoma. The tumor which arose in the posterior fossa was first diagnosed in 2007 when first surgical resection was performed outside our institute. Multiple operations were performed after that due to tumor relapse. Multiple lung nodules were discovered incidentally during a VP shunt survey. Biopsy from the lung nodules displayed identical histomorphology to the primary brain tumor.

Timing of adjuvant radiotherapy and treatment outcome in childhood ependymoma

BACKGROUND

Several trials incorporating adjuvant focal RT for treatment of young children with ependymoma have demonstrated improved survival with acceptable adverse effects. The optimal timing of RT administration is, however, unknown.

PROCEDURE

A retrospective review of territory-wide database was performed to identify pediatric patients with ependymoma diagnosed between 1995 and 2011. OS and EFS were compared between patients receiving upfront RT (<150 days of diagnosis), delayed RT (≥150 days of diagnosis), or no RT.

RESULTS

Thirty-one patients with intracranial ependymoma were identified. Median age was 3.5 years and 14 (45%) were male. Primary tumor was supratentorial in 10 (32%) and infratentorial in 21 (68%). All patients underwent initial surgery, with gross-total resection (GTR) in 27 (87%). Twelve (39%) received upfront RT, 10 (32%) had delayed RT and 9 (29%) had no RT. During the study period, there were 11 relapses (35%) and 10 deaths (32%). Five-year OS was 69.9% and 5yr-EFS was 49.3%. In univariate analysis, GTR led to improved OS (P < 0.001) and EFS (P = 0.004); superior OS and EFS was observed in patients who received RT when compared with those without (P = 0.018 and 0.011, respectively). Upfront RT also resulted in better OS and EFS than delayed RT (P = 0.049 and 0.014, respectively). No significant effect on survival was observed with age, sex, tumor location, RT dosage, and protocol used. In multivariate analysis, GTR significantly improved OS (P = 0.002) and EFS (P = 0.004).

CONCLUSIONS

Our results support the early initiation of adjuvant RT in the multi-modal management of pediatric ependymomas.

Surveillance imaging in children with malignant CNS tumors: low yield of spine MRI

Magnetic resonance imaging (MRI) is routinely obtained in patients with central nervous system (CNS) tumors, but few studies have been conducted to evaluate this practice. We assessed the benefits of surveillance MRI and more specifically spine MRI in a contemporary cohort. We evaluated MRI results of children diagnosed with CNS tumors from January 2000 to December 2011. Children with at least one surveillance MRI following the diagnosis of medulloblastoma (MB), atypical teratoid rhabdoid tumor (ATRT), pineoblastoma (PB), supratentorial primitive neuroectodermal tumor, supratentorial high-grade glioma (World Health Organization grade III-IV), CNS germ cell tumors or ependymoma were included. A total of 2,707 brain and 1,280 spine MRI scans were obtained in 258 patients. 97% of all relapses occurred in the brain and 3% were isolated to the spine. Relapse was identified in 226 (8%) brain and 48 (4%) spine MRI scans. The overall rate of detecting isolated spinal relapse was 9/1,000 and 7/1,000 for MB patients. MRI performed for PB showed the highest rate for detecting isolated spinal recurrence with 49/1,000. No initial isolated spinal relapse was identified in patients with glioma, supratentorial primitive neuroectodermal tumor and ATRT. Isolated spinal recurrences are infrequent in children with malignant CNS tumors and the yield of spine MRI is very low. Tailoring surveillance spine MRI to patients with higher spinal relapse risk such as PB, MB with metastatic disease and within 3 years of diagnosis could improve allocation of resources without compromising patient care.

Isolation of tumor spheres and mesenchymal stem-like cells from a single primitive neuroectodermal tumor specimen

PURPOSE

It has been reported that cancer stem cells (CSCs) can be isolated from primitive neuroectodermal tumor (PNET) specimens. Moreover, mesenchymal stem-like cells (MSLCs) have been isolated from Korean glioma specimens. Here, we tested whether tumor spheres and MSLCs can be simultaneously isolated from a single PNET specimen, a question that has not been addressed.

METHODS

We isolated single-cell suspensions from PNET specimens, then cultured these cells using methods for MSLCs or CSCs. Cultured cells were analyzed for surface markers of CSCs using immunocytochemistry and for surface markers of bone marrow-derived mesenchymal stem cells (BM-MSCs) using fluorescence-activated cell sorting (FACS). Tumor spheres were exposed to neural differentiation conditions, and MSLCs were exposed to mesenchymal differentiation conditions. Possible locations of MSLCs within PNET specimens were determined by immunofluorescence analysis of tumor sections.

RESULTS

Cells similar to tumor spheres and MSLCs were independently isolated from one of two PNET specimens. Spheroid cells, termed PNET spheres, were positive for CD133 and nestin, and negative for musashi and podoplanin. PNET spheres were capable of differentiation into immature neural cells and astrocytes, but not oligodendrocytes or mature neural cells. FACS analysis revealed that adherent cells isolated from the same PNET specimen, termed PNET-MSLCs, had surface markers similar to BM-MSCs. These cells were capable of mesenchymal differentiation. Immunofluorescence labeling indicated that some CD105(+) cells might be closely related to endothelial cells and pericytes.

CONCLUSION

We showed that both tumor spheres and MSLCs can be isolated from the same PNET specimen. PNET-MSLCs occupied a niche in the vicinity of the vasculature and could be a source of stroma for PNETs.

Study of chromosome 9q gain, Notch pathway regulators and Tenascin-C in ependymomas

Ependymomas are relatively uncommon tumours of the central nervous system which arise from the ependymal lining of the ventricles and spinal canal. The molecular changes leading to ependymal oncogenesis are not completely understood. We examined chromosome 9q33-34 locus for gain, potential oncogenes at this locus (Notch-1 and Tenascin-C) and Notch pathway target genes (Hes-1, Hey-2 & C-myc) in ependymomas by fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC), respectively, to assess if they have any correlation with clinical characteristics. We analyzed 50 cases of ependymomas by FISH for 9q gain and by IHC for Notch-1 and its target gene proteins (Hes-1, Hey-2 and C-myc) expression. We also performed IHC for Tenascin-C to rule out any correlation with aggressiveness/grade of tumour. FISH study revealed significant chromosome 9q gain in ependymomas of adult onset (age > 18 years) and spinal cord origin. Notch-1 showed significantly more frequent immunohistochemical expression in supratentorial and anaplastic ependymomas. Tenascin-C (TN-C) expression was significant in intracranial, childhood (age ≤ 18 years) and anaplastic ependymomas. Of the three Notch pathway target gene proteins (Hes-1, Hey-2 and C-myc), Hes-1 and C-myc expression showed significant correlation with anaplastic and adult onset ependymomas, respectively. Genetic alterations are independent prognostic markers in ependymomas. A clinicopathological correlation with various molecular signatures may be helpful in the development of new therapeutic targets.

Children's Oncology Group's 2013 blueprint for research: central nervous system tumors

In the US, approximately 2,500 children are diagnosed annually with brain tumors. Their survival ranges from >90% to <10%. For children with medulloblastoma, the most common malignant brain tumor, 5-year survival ranges from >80% (standard-risk) to 60% (high-risk). For those with high-grade gliomas (HGGs) including diffuse intrinsic pontine gliomas, 5-year survival remains <10%. Sixty-five percent patients with ependymoma are cured after surgery and radiation therapy depending on the degree of resection and histopathology of the tumor. Phase II trials for brain tumors will investigate agents that act on cMET, PDGFRA, or EZH2 in HGG, DIPG, or medulloblastoma, respectively. Phase III trials will explore risk-based therapy stratification guided by molecular and clinical traits of children with medulloblastoma or ependymoma.

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.

Genetic expression profiles of adult and pediatric ependymomas: molecular pathways, prognostic indicators, and therapeutic targets

Ependymomas are tumors that can present within either the intracranial or spinal regions. While 90% of all pediatric ependymomas are intracranial, spinal cord ependymomas are more commonly found in patients 20-40 years old. Treatment for spinal lesions has achieved local control rates up to 100% following gross total resection, while pediatric intracranial tumors have 40-60% mortality. Given the inability to effectively treat ependymomas with current standard practices, researchers have focused their efforts on evaluating chromosomal alterations, genetic expression profiles, epigenetic events, and molecular pathways. While these studies have provided critical insight into the potential mechanisms underlying ependymoma pathogenesis, understanding of the intricate interplay between the various pathways involved in tumor initiation, development, and progression will require deeper investigation. However, several potential prognostic markers and therapeutic targets have been identified, providing key areas of focus for future research. The utilization of unique genetic expression profiles based upon patient age, tumor location, tumor grade, and subtype has revealed a multitude of findings warranting further study. Inspection of various molecular pathways associated with ependymomas may establish the foundation for developing novel therapies capable of achieving significant clinical improvements with individualized regimens specifically designed for personalized treatment strategies.

Extraneural ependymoma: distant bone, lung, liver, and lymph node metastases following bevacizumab

Extraneural metastases of ependymoma are rare, and have been reported in the lungs, lymph nodes, pleura, mediastinum, liver, diaphragmatic muscle, and bone. We report a case of anaplastic ependymoma with distant metastases to the vertebral bones, lungs, liver, and lymph nodes following treatment with bevacizumab. Recent research has hypothesized that angiogenic tumors may develop means of resistance to antiangiogenic therapies, and some evidence suggests potential for antiangiogenic therapies to promote additional means for cancer spread. Nevertheless, antiangiogenic therapies continue to demonstrate potential as potent therapies for the treatment of many cancers, and should continue to be researched for future uses.

Chromosomal anomalies and prognostic markers for intracranial and spinal ependymomas

Ependymomas are neoplasms that can occur anywhere along the craniospinal axis. They are the third most common brain tumor in children, representing 10% of pediatric intracranial tumors, 4% of adult brain tumors, and 15% of all spinal cord tumors. As the heterogeneity of ependymomas has severely limited the prognostic value of the World Health Organization grading system, numerous studies have focused on genetic alterations as a potential basis for classification and prognosis. However, this endeavor has proven difficult due to variations of findings depending on tumor location, tumor grade, and patient age. While many have evaluated chromosomal abnormalities for ependymomas as a whole group, others have concentrated their efforts on specific subsets of populations. Here, we review modern findings of chromosomal analyses, their relationships with various genes, and their prognostic implications for intracranial and spinal cord ependymomas.

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.