EPENDYMOMA

doi:10.1093/neuonc/nos099

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-01. POST-OPERATIVE RADIOTHERAPY FOR FOURTH VENTRICLE EPENDYMOMA IN CHILDREN BELOW 3 YEARS OLD: GOOD PRELIMINARY RESULTS

Mohamed Zaghloul ¹, Mohamed Elbeltagy ¹, Amr Mousa ¹, Eman Eldebawy ¹, Amr Amin ¹

Abstract

BACKGROUND: Children's brain is continuously developing. Radiation oncologists usually refrain from radiating brain in the first 3 years. PURPOSE: To identify the feasibility of irradiating infratentorial ependymoma postoperatively in children below 3 years and to report on its effect on survival and toxicity. PATIENTS AND METHODS: Thirty seven children were diagnosed as ependymoma in children's Cancer Hospital, Egypt (CCHE) during the period from Jan 2008 to Dec 2010. Out of these, 6 (16.2%) were below 3 years old. They were all males with a median age of 20.5 (range: 13-25) months. Two tumors were totally excised having anaplastc type (G III). The other 4 were excised with residual left infiltrating the brainstem. The histopathology was G II in 2 patients and anaplastic in the other 2. Only two patients received chemotherapy prior to subtotal excision. All 6 children received intensity-modulated radiotherapy (IMRT) to decrease the dose to brainstem. RESULTS: All patients tolerated the prescribed radiotherapy dose that ranged from 5400 to 5940 cGy with a median of 5580 cGy in 42-45 days without gap (except in one patients, 4 days, for social reason). The immediate side effects were partial alopecia in 5 patients, nausea and vomiting (grade II) in 2 patients and anorexia in all patients. All 6 patients were alive for a median of 33 months (range 8-38). Four out of the 6 (66.7%) had MRI free of tumor at a range of 18-34 months. The other 2 patients showed stationary tumor size on MRI. One patient had cystic cavitations on MRI, while another one had ototoxcity that needed hearing aids. Both patients received chemotherapy preoperatively. CONCLUSIONS: Radiotherapy for pediatric infratentorial ependymoma leads to good results in children below 3 years. Though of the relatively short follow up yet, the delayed complications are limited and outweighed the survival benefit.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-02. ANAPLASTIC EPENDYMOMA AND DIFFUSE ASTROCYTOMA PRESENTING AS SYNCHRONOUS PRIMARY BRAIN TUMORS IN A CHILD (CASE REPORT)

Zdenek Pavelka ¹, Vladimira Vranova ², Iveta Valaskova ², Lenka Tomasikova ³, Alexandra Oltova ³, Jiri Ventruba ⁴, Zdenek Mackerle ⁴, Leos Kren ⁵, Jarmila Skotakova ⁶, Karel Zitterbart ¹, Jaroslav Sterba ¹

Abstract

The simultaneous occurence of multiple different primary brain tumors in children is extremly rare. The authors describe the case of 7-years old boy who presented with a short history of intracranial hypertension. MR imaging showed two brain masses with different MR characteristics (one in the posterior fossa and the next in the right temporal lobe). The patient underwent a gross total resection of both lesions leading to the complete remission. Pathological examination revealed the posterior fossa tumor and temporal tumor to be anaplastic ependymoma and diffuse astrocytoma, respectively. The child was subsequently treated by conformal irradiation on the posterior fossa ependymoma, no specific adjuvant treatment for the completely resected diffuse astrocytoma was initiated. The boy is now on follow-up with the continuing remission. Chromosome analysis of ependymoma revealed clone with 47 chromosomes and translocation between chromosomes 1 and 6 - 47,XY, + der(1)t(1;19), der(6)t(1;6) [3/23]. Molecular cytogenetic analysis with DNA isolated from fresh tumor tissue confirmed duplication of long arm of chromosome 1 ((1)(q11.1qter)) and deletion of (6)(q12qter) region. In addition, it disclosed duplication of short arm of chromosome 19. FISH with whole chromosome painting probes for chromosomes 1 and 19 disclosed translocation between these two chromosomes. Molecular genetic analysis of RB1 and NF2 genes at the level of nucleic acids based on direct sequencing and MLPA did not reveal any changes in comparison with health control. The analysis of TP53 gene showed homozygote substitution C > G which led to amino acid change prolin to arginin at position 72. This substitution has no influence on protein function. Cytogenetic analysis of diffuse astrocytoma was not possible becasue the tissue was only stored in paraffine. CONCLUSION:. Two separate lesions in brain can represent a synchronous malignancy. An individual therapeutic approach should be established. The potential role of various factors in the development of multiple or synchronous primary brain tumors remains still speculative.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-03. THE NOVEL HUMAN HIGH-RISK EPENDYMOMA STEM CELL MODEL DKFZ-EP1NS REVEALS THE DIFFERENTIATION-INDUCING POTENTIAL OF TREATMENT WITH THE HISTONE DEACETYLASE INHIBITOR VORINOSTAT

Till Milde ¹, Susanne Kleber ³, Andrey Korshunov ⁴, Hendrik Witt ⁵, Thomas Hielscher ⁶, Philipp Koch ⁷, Hans-Georg Koch ⁸, Manfred Jugold ⁹, Hedwig E Deubzer ¹, Ina Oehme ¹, Marco Lodrini ¹, Hermann-Josef Gröne ¹⁰, Axel Benner ⁶, Oliver Brüstle ⁷, Richard J Gilbertson ¹¹, Andreas von Deimling ⁴, Andreas E Kulozik ², Stefan M Pfister ⁵, Martin-Villalba Ana ³, Olaf Witt ¹

Abstract

Curative therapy of incompletely resected ependymomas remains a challenge despite intensive radio- and chemotherapy. In the past, the development of novel treatments has been difficult due to the lack of appropriate models. We here report on the generation of a novel high risk cytogenetic group 3 and molecular group C ependymoma model (DKFZ-EP1NS). This model is based on primary ependymoma cells obtained from a patient with metastatic supratentorial ependymoma. It displays stem cell features like self renewal capacity, differentiation capacity and specific marker expression. A high tumorigenic potential was seen in vivo, and xenografts phenotypically recapitulated the original tumor in a niche dependent manner. Gene expression profiling revealed transcriptome plasticity, enabling a shift from a neural stem cell-like program towards the profile of a primary ependymoma tumor upon in vivo transplantation. Serial transplantation of DKFZ-EP1NS cells from orthotopic xenografts yielded secondary tumors in half the time compared to the initial transplantation. The cells were resistant to temozolomide, vincristine and cisplatin, but responded well to histone deacetylase inhibitor (HDACi)-treatment in therapeutically achievable concentrations. In vitro treatment of DKFZ-EP1NS cells with the HDACi Vorinostat induced neuronal differentiation associated with loss of stem cell-specific properties. This is the first ependymoma model of a cytogenetic group 3 and molecular subgroup C ependymoma based on a human cell line with stem cell-like properties, demonstrating the differentiation inducing therapeutic potential of the HDACi vorinostat.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-04. NESTIN PROTEIN EXPRESSION IS AN INDEPENDENT PROGNOSTIC MARKER IN EPENDYMOMA AND DISCRIMINATES WHO II EPENDYMOMA WITH POOR OUTCOME

Till Milde ¹, Thomas Hielscher ³, Hendrik Witt ⁴, Marcel Kool ⁴, Stephen C Mack ⁵, Hedwig E Deubzer ¹, Ina Oehme ¹, Marco Lodrini ¹, Axel Benner ³, Michael D Taylor ⁵, Andreas von Deimling ⁶, Andreas E Kulozik ², Stefan M Pfister ⁴, Olaf Witt ¹, Andrey Korshunov ⁶

Abstract

Ependymomas are common brain tumors in children and adults and can arise throughout the CNS. Ependymomas are stratified into grade I-III according to the current WHO classification. Currently, many treatment protocols classify grade I and II ependymomas as low-risk tumors with patients recieving less intense or no chemotherapy after surgery and irradiation. This is in contrast to grade III (anaplastic) ependymomas, which are considered high-risk tumors requiring additional chemotherapy. However, it is recognized that the difference between grade II and III is virtually arbitrary in daily practice, and thus may contribute to imprecise risk stratification. Therefore, prognostic markers enabling more precise stratification that can be routinely used are urgently needed. Here we describe that high protein expression of a marker for neural stem and progenitor cells, Nestin, as assessed by immunohistochemistry (IHC) in n = 379 ependymoma samples, is associated with poor prognosis. Most importantly, Nestin separates grade II ependymomas into two groups with distinct survival, with Nestin positive grade II ependymomas having the same prognosis as grade III ependymomas. Additional information is gained when combining Nestin IHC with classifications according to cytogenetic groups 1-3, and/or posterior fossa group A and B (PFA/PFB). Multivariable analysis demonstrates that Nestin positivity is an independent marker for poor progression-free (PFS) and overall survival (OS). Finally, analysis of Nestin co-regulated genes in two separate datasets (n = 75 and n = 102 ependymoma samples, respectively) revealed co-regulation of developmental and epigenetic processes. In summary, our data suggest Nestin as a useful novel marker for ependymoma risk stratification adding additional information to both old and novel risk-stratifications, with the advantage of being easily implementable in routine diagnostics.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-05. CERVICAL LYMPH NODES DISSEMINATION OF A RECURRENT SUPRATENTORIAL EPENDYMOMA

Fanny Fouyssac ¹, Emmanuelle Schmitt ¹, Ludovic Mansuy ¹, Jean-Claude Marchal ¹, Laurent Coffinet ¹, Valerie Bernier ², Pascal Chastagner ¹

Abstract

A 32-month-old boy presented with a history of raised intracranial pressure since two weeks. MRI of the brain showed a right frontal lobe cystic and solid lesion (7 x 7 x 7 cm). A complete macroscopic resection of the tumor was performed. Histology revealed a clear cell ependymoma. Due to the complete resection and the young age, only a close clinical and radiological surveillance was planned. Twenty-one months later, MRI showed a relapse at the initial site and nearby in the right temporal lobe. A second complete macroscopic resection of both lesions was performed. The pathological analysis confirmed the diagnosis of clear cell ependymoma. Considering the parents' refusal for delivering radiotherapy and the absence of therapeutic target for chemotherapy, only surveillance was done. Sixteen months later, MRI showed another focal tumor recurrence within the initial site. A third complete macroscopic resection was performed and protontherapy was then planned. However, a painless pre-auricular mass occurred prior to start radiotherapy. The biopsy concluded to the diagnosis of a lymph node metastasis of the ependymoma. Body CT, PET scans and bone marrow biopsies eliminated other metastases. Chemotherapy using vincristine, etoposide and cyclophosphamide (VEC protocol) was initiated. After two courses, the tumor size reduced by 27%. A third course was ineffective. Surgery with parotidectomy, right lymph node cervical curage and excision of the lower part of the scalp scar was performed. The parotid gland, all the lymph nodes except one and the skin were normal. The primitive and metastatic areas were irradiated at the dose of 59.4 Gy. The child is in complete remission since 6 months off therapy. This is another case of a slow progressing ependymoma that could disseminate outside the CNS from primary tumor via surgical excision.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-06. PRIMARY SPINAL CORD EPENDYMOMA: A MULTI-INSTITUTIONAL EUROPEAN SERIES OF 54 PATIENTS

Daniela Sperl ¹, Stergios Zacharoulis ², Maura Massimino ³, Elisabetta Schiavello ³, Barry Pizer ⁴, Caroline Piette ⁵, Lidija Kitanovski ⁶, Katja von Hoff ⁷, Franz Quehenberger ⁸, Stefan Rutkowski ⁷, Martin Benesch ¹

Abstract

PURPOSE: The aim of this multi-institutional cooperative project is to collect and analyze clinical data of children and adolescents with primary spinal cord ependymoma (PSCE) within the network of the SIOP Europe Brain Tumour Group (SIOP-E BTG). PATIENTS AND METHODS: Fifty-four patients (males, n = 29) with PSCE were included. Median age at diagnosis was 13.4 years. Median duration of symptoms was 2 months. Twenty-five patients had WHO grade II, 16 patients WHO grade I (myxopapillary) and 10 patients WHO grade III PSCE (data missing, n = 3). RESULTS: A gross-total-resection (GTR) was achieved in 31 patients. Nineteen patients underwent a less than GTR; two had a biopsy and in the remaining two data on the extent of resection was missing. Twenty-eight patients underwent primary adjuvant radiotherapy (grade I, n = 8; grade II, n = 13; grade III; n = 6, grade unknown, n = 1). Chemotherapy was performed in 10 patients (grade I, n = 1; grade II, n = 6; grade III, n = 3). With a median follow-up of 4.5 years 48% of patients (n = 26) are presently alive in complete remission. Twenty patients are alive with either stable (n = 14) or progressive (n = 6) residual tumors. Five patients died due to progressive disease. Progression-free (PFS) and overall survival (OS) at 5 years are 71% and 98% for the entire cohort; PFS for WHO grade I, II, and III PSCE is 50%, 86%, and 68% (p = 0.026). Corresponding figures for OS are 100%, 100%, and 88% (p = 0.13). CONCLUSIONS: A GTR is achievable in about 50% of children with PSCE. A comparable proportion of patients received adjuvant treatment, mainly based on radiotherapy. Patients with WHO grade I PSCE have the highest incidence of relapse, followed by WHO grade III PSCE. Although a considerable number of patients relapse, OS at 5 years is favorable. Data collection and analysis will be continued within the SIOP-E BTG.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-07. ACTINOMYCIN-D TREATMENT RE-ESTABLISHES THE TUMOR-SUPPRESSIVE FUNCTION OF P53 IN HIGH-RISK EPENDYMOMAS

Theophilos-Dimitrios Tzaridis ¹, Hendrik Witt ¹, Till Milde ⁴, Sebastian Bender ¹, Elke Pfaff ¹, Sebastian Barbus ¹, Josephine Bageritz ¹, David-Thomas-Warwick Jones ¹, Andreas Kulozik ², Peter Lichter ¹, Andrey Korshunov ³, Olaf Witt ⁴, Stefan-Michael Pfister ¹

Abstract

Ependymomas are thought to arise from the subventricular zone and comprise the third most common pediatric brain tumour. It is known that aberrant expression of non-functional p53 is associated with inferior outcome in ependymoma. To unravel the underlying mechanism of p53 inactivation in ependymoma, we performed TP53 mutation analysis in 130 primary tumours and identified a mutation rate of only 3%. We studied p53 protein expression by immunohistochemistry on 398 primary intracranial ependymomas and found that p53-accumulation occurs much more frequently (22%). This correlated significantly with worse progression-free and overall survival. We recently defined biological and clinical subgroups of ependymoma with a substantial proportion of high-risk tumours harbouring a homozygous CDKN2A deletion. Since TP53 mutations are rare in ependymoma, the main mechanism of loss of p53 function despite protein accumulation might be p53 destabilization due to absence of p14 and subsequently excessive MDM-2 activity. In order to assess the potential reversibility of this process and to reactivate p53 through MDM-2 inhibition, we evaluated the effects of low-dose Actinomycin-D treatment in two ependymoma cell lines. Cell viability assays were performed after treatment with different concentrations of the agent to define the IC-50 confirming low-dose effects for both cell lines (IC-50: 0.2-0.7nM). Then we carried out transcriptome analyses (Agilent-44K) of untreated, low-dose and high-dose Actinomycin-D treated cells. Interestingly, differentially expressed genes between low-dose (5nM) and high-dose (100nM) treated cells included several p53-dependent markers (i.e. GADD45, PUMA). We further demonstrated by Western blotting the reestablishment of components of the p53 complex (p21, MDM-2) after treatment. The apoptotic effect of Actinomycin-D was determined by flow cytometry, showing that low-dose Actinomycin-D induced apoptosis in a more effective way than high-dose. These results indicate that Actinomycin-D treatment of ependymomas reactivates p53 and could comprise a rational therapeutic approach for a subset of high-risk ependymoma patients.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-08. LONG-TERM SURVIVAL OF SUPRATENTORIAL ECTOPIC EPENDYMOMA IN CHILD

Shi-Hun Song ¹, Chang-Woo Kang ¹, Seon-Hwan Kim ¹

Abstract

Ependymoma is a rare tumor developed from ependymal cells and belongs to the group of neuroglial tumors. It may be located in any part of the central nervous system, but shows a preference for the ventricular surface and approximately two-thirds of them are infratentorial. We present an unusual case of a 7-year-old boy with a supratentorial ependymoma located in the right side frontoparietal parenchyma and showing no continuity with the ventricular system. The patient presented with a one-week history of headache, vomiting and mild left side motor weakness. Magnetic resonance imaging showed a large sized cystic mass with highly enhancing capsule of uneven thickness located in the right side frontal and parietal parenchyma. The patient underwent gross total resection of the tumor. The surgical findings showed no relationship with the lateral ventricular system. Pathological examination revealed histological features consistent with an ependymoma. After pathological diagnosis was made, we checked whole spine MRI with enhancement to evaluate spinal dissemination. Fortunately, there was no evidence of spinal seeding on MRI. Postoperatively, focal radiation therapy was carried out. Currently, 11 years follow-up, the patient remained neurologically intact and his school life is very active and showed no evidence of tumor recurrence on neuroradiological imaging studies. The clinical features, radiologic images, pathology and surgical management of ependymoma is discussed and the relevant literature is briefly reviewed.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-09. OUTCOME OF CHILDREN WITH MYXOPAPILLARY EPENDYMOMA

Pratiti Bandopadhayay ¹, Nicole Ullrich ², Liliana Goumnerova ³, R Michael Scott ³, V Michelle Silvera ⁴, Keith L Ligon ⁵, Karen J Marcus ⁶, Nathan Robison ¹, Peter E Manley ¹, Susan Chi ¹, Mark W Kieran ¹

Abstract

BACKGROUND: Myxopapillary ependymomas (WHO grade 1) are rare pediatric tumors that most commonly occur in the spine. They account for 10-20% of all pediatric spinal tumors. Standard treatment is maximal surgical excision. There is little data on long-term outcome and need for adjuvant therapies in children. METHOD: We performed an IRB approved retrospective review of children treated at the Children's Hospital Boston between 1982 and 2012. Eighteen children were diagnosed with myxopapillary ependymoma. RESULTS: The median age at diagnosis was 13.5 years (range 8-19) and 50% were males. Children most commonly presented with pain, leg weakness and sphincter disturbance. The lower thoracic and lumbar spine was the most frequent location. Eight children had metastatic disease at presentation (44%), with the thecal sac representing the most common site. All children had gross total resection of the primary tumor, and three children with metastatic disease underwent radiation treatment immediately post resection. The 5 year event free survival was 53.9% (± 13.25%) and overall survival was 100%. The presence of metastatic disease at diagnosis was a prognostic factor, with a 5 year EFS of 100% in children with localized disease and only 12.5% (± 11.7%) in children with metastatic disease (p = 0.0016). Five children received radiation therapy upon recurrence. Two children experienced further progression of disease after radiation therapy and were treated with chemotherapy, one of whom developed secondary AML. Two other children subsequently developed intracranial metastasis. CONCLUSION: Myxopapillary ependymoma is rare in children. Metastatic disease is a poor prognostic factor for EFS. Although children have an excellent overall survival, they have a high incidence of disease progression and therapy related morbidity. Our data suggest a higher incidence of disseminated disease in children, including development of intracranial metastasis.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-10. SIX CASES OF EXTRASPINAL EPENDYMOMAS: THE AIEOP EXPERIENCE

Elisabetta Schiavello ¹, Veronica Biassoni ¹, Paolo Pierani ², Simone Cesaro ³, Massimino Maura ¹

Abstract

Primary extraspinal ependymomas are rare and usually occur in the subcutaneous sacrococcygeal or presacral regions. Due to their rarity the treatment strategy is still controversial. In the last 15 years 6 children were treated in Italy: median age at diagnosis was 10 years, 3 were females and 3 males. All the patients had primary sacrococcygeal primaries; only one was metastatic (acetabolum and ischium). 5/6 received primary surgery with one only complete removal; in two cases the coccyx was infiltrated, but only in one case coccigectomy was performed. In one patient, the one with bone metastases, only primary diagnostic biopsy was performed. The histology according to the WHO classification was myxopapillary-grade I (3/6) and grade II variety (3/6). Adjuvant therapy was applied only in the metastastic patient: standard dose polichemotherapy was administered followed by local radiotherapy. 2/6 experienced a recurrence (3 and 8 years after the diagnosis): the first presented with inguinal lymphnodal metastases and the second with local recurrence, pelvic (broad ligament), lung and lymphnodal localisations. They were treated with a salvage chemotherapy (including high dose sequential chemotherapy, myeloablative melphalan and peripheral autologous stem cell transplantation in one case) and radiotherapy achieving complete remission. All 6 patients are alive and actually have no evidence of disease. Our limited experience suggests that: surgical removal is the favoured treatment (in case of localised disease); coccygectomy is not associated with a reduction of the recurrence rate. Despite a resistence to chemotherapy when arising in axial sites, chemotherapy (including myeloablative schedule) proved to be useful secondary treatment options in case of recurrent disease.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-11. THE GENETIC HETEROGENEITY OF POSTERIOR FOSSA EPENDYMOMA

Hendrik Witt ¹, Steve Mack ², Natalie Jäger ³, David T W Jones ¹, Sebastian Bender ¹, Adrian Stütz ⁴, Till Milde ⁵, Paul A Northcott ², Daniel W Fults ⁶, Nalin Gupta ⁷, Matthias Karajannis ⁸, Andreas E Kulozik ¹⁰, Andreas von Deimling ⁹, Olaf Witt ⁵, James T Rutka ², Peter Lichter ¹¹, Jan Korbel ⁴, Andrey Korshunov ¹², Michael D Taylor ², Stefan M Pfister ¹

Abstract

Ependymoma is a malignant brain tumor in children and adults. In childhood, brain tumors are the most common cause of cancer-related death. Despite improvements in the biological understanding and classification of these tumors, this disease remains incurable for as many as approx. 40% of patients with current treatment regimens. Despite showing very homogeneous histology, independent of localization and aggressiveness, ependymomas display distinct biological behavior that suggest clear subgroups within the disease. Two independent cohorts of 102 and 75 ependymomas were studied by mRNA expression profiling and aCGH. Multiple statistical analyses consistently revealed two subgroups of posterior fossa (PF) ependymoma in both data sets, including subgroup-specific chromosome aberrations. Biological signaling pathways distinguishing these PF subgroups were identified by gene set enrichment analysis, and subgroup-specific markers were validated by immunohistochemistry of 265 PF ependymomas on a tissue microarray. Additionally, we performed whole-exome sequencing (Illumina HiSeq technology) using the Agilent SureSelect 50Mb Exome library enrichment in an independent cohort of 38 PF ependymomas representing both subgroups, to identify somatic mutations which may explain the genomic disparity. PF ependymoma can be classified into group-A and group-B tumors, showing significant differences in outcome, and clearly distinct biological characteristics. Patients in group-A are mainly young children, have laterally located tumors with a balanced genome, and are much more likely to have a fatal outcome as compared to group-B patients. Evaluation of somatic mutations based on deep-sequencing revealed around 453 different mutations in total, an average of ≈13 mutations per tumor, and highlighted several genes not previously implicated in ependymoma tumorigenesis. Identification of subgroup-specific mutations will help to discriminate between the two PF ependymoma entities and to identify subgroup-specific drug targets, in turn allowing for better prognostication and treatment of individual cases in future ependymoma trials.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-12. REIRRADIATION FOR RECURRENT CHILDHOOD EPENDYMOMA WITH IMAGE-GUIDED INTENSITY MODULATED RADIOTHERAPY (IG-IMRT): INITIAL EXPERIENCE

Ana Carolina Pires de Rezende ¹, Michael Jenwei Chen ¹, Nasjla Saba da Silva ², Andréa Cappellano ², Sergio Cavalheiro ², Eduardo Weltman ¹

Abstract

PURPOSE: Pediatric primary central nervous system (CNS) tumors are seldom reirradiated due to toxicity concerns and sparse data regarding its efficacy. After St. Judés analysis showing good results on reirradiation for recurrent ependymomas, radiation therapy (RT) became a treatment option for these children. We report preliminary results of disease control and short term toxicity for patients with recurrent ependymoma treated with surgery and a second course of radiotherapy (RT2). METHODS AND MATERIALS: Between February 2010 and May 2011, 13 children from IOP/UNIFESP with ependymoma were referred to HIAE to RT, four of them with local recurrent disease, previously treated with surgery, chemotherapy and RT. After maximum safe resection, focal reirradiation was performed with image-guided intensity modulated radiotherapy (IG-IMRT), aiming the surgical bed and any site of persistent disease, with reduced margins. After RT2, patients were prospectively followed regarding disease control and short term toxicity. RESULTS: Time from first course of RT (RT1) and RT2 ranged from 29 to 61 months. Mean age at RT1 was 5.1 years old and 8.6 years old for RT2. RT1 and RT2 doses varied from 54 to 55.8 Gy and 50.4 to 54 Gy, respectively, with mean combined doses of 108.5 Gy. After a follow-up interval ranging from 9 to 24 months, none of the patients presented major side effects or deterioration of previous neurological symptoms. Three patients showed disease control and one eventually died from local tumor progression after 22 months of follow-up. The 3 remaining patients are still alive, 1 with stable disease and 2 with no evidence of disease, 10 to 24 months after RT2. CONCLUSIONS: CNS focal reirradiation with IG-IMRT for patients with relapsed ependymoma seems to provide adequate local control without high toxicity rates. However, further follow-up is required to better evaluate long-term survival and treatment-related side effects.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-13. A NOVEL LENTIVIRUS-BASED SCREEN FOR EPENDYMOMA TUMOR SUPPRESSOR GENES

Spencer Currle ¹, Radhika Thiruvenkatam ¹, Mohankumar Murugesan ¹, Tanya Kranenburg ¹, Timothy Phoenix ¹, Kirti Gupta ¹, Richard Gilbertson ¹

Abstract

Ependymomas include a diverse group of central nervous system (CNS) tumors that are incurable in up to 40% of cases. Previously, we developed a novel cross-species genomics approach to detect candidate oncogenes and tumor suppressor genes (TSGs) of human ependymoma subgroups, and introduced these into transcriptome-matched mouse neural stem cells (NSCs) to develop the first accurate mouse models of the disease (Johnson et al., Nature 2010). Here, we report a lentiviral-based approach that has allowed us to screen all 40 candidate TSGs of human ependymoma, and identify several new candidate drivers of ependymoma: none were previously implicated in the disease. We have compiled pools of short hairpin RNAs (shRNAs) targeting the mouse orthologs of all 40 candidate TSGs (3 per candidate; candidates are genes both deleted and under-expressed in human ependymoma) and tested their ability to promote tumorigenesis in our mouse ependymoma model. shRNAs were divided into 4 pools of 30 viruses each, targeting 10 candidate TSGs. Transcriptome matched NSCs were transduced with EPHB2 (that we have validated as an ependymoma oncogene) and vector control, or EPHB2 and one of the four virus pools. Transduced NSCs were then transplanted into the forebrain subventricular zone of 30 immuno-compromised mice for each pool. Tumors from each pool exhibited a significant decrease in latency, suggesting suppression of functional TSGs. Using luminex deep sequencing to measure the frequency of individual shRNA integrations within genomic DNA extracted from 88 tumors, we identified several target-specific shRNAs that became enriched during tumorigenesis, indicating clonal expansion of those cells that gain a growth advantage upon TSG knock down. This approach has identified novel candidate TSGs that contribute to ependymoma development in our model. Targeting these novel TSGs, we aim to model each of the 9 ependymoma subtypes to further our efforts in disease prevention, diagnoses, and treatment.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-14. DNA METHYLATION IN EPENDYMOMA

Hazel Rogers ¹, John-Paul Kilday ¹, Cerys Mayne ¹, Jennifer Ward ¹, Martyna Adamowicz-Brice ¹, Ed Schwalbe ², Steven Clifford ², Beth Coyle ¹, Richard Grundy ¹

Abstract

Epigenetic alterations, including methylation, have been shown to be an important mechanism of gene silencing in cancer. Ependymoma has been well characterized at the DNA copy number and mRNA expression levels. However little is known about DNA methylation changes. To gain a more global view of the methylation profile of ependymoma we conducted an array based analysis. Our data demonstrated tumors to segregate according to their location in the CNS, which was associated with a difference in the global level of methylation. Supratentorial and spinal tumors displayed significantly more hypermethylated genes than posterior fossa tumors, similar to the ‘CpG island methylator phenotype' (CIMP) identified in glioma and colon carcinoma. This hypermethylated profile was associated with an increase in expression of genes encoding for proteins involved in methylating DNA, suggesting an underlying mechanism. An integrated analysis of methylation and mRNA expression array data allowed us to identify methylation induced expression changes. Most notably genes involved in the control of cell growth and death and the immune system were identified, including members of the JNK pathway and PPARG. In conclusion, we have generated a global view of the methylation profile of ependymoma. The data suggests epigenetic silencing of tumor suppressor genes is an important mechanism in the pathogenesis of supratentorial and spinal, but not posterior fossa ependymomas. Hypermethylation correlated with a decrease in expression of a number of tumor suppressor genes and pathways that could be playing an important role in tumor pathogenesis.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-15. PI3K PATHWAY IN EPENDYMOMA

Hazel Rogers ¹, Cerys Mayne ¹, John-Paul Kilday ¹, Beth Coyle ¹, Richard Grundy ¹

Abstract

Ependymoma is the third most common pediatric tumor of the central nervous system. Patients with these tumors have a relatively poor prognosis. Tumors are currently treated with surgical resection followed by radiotherapy, with the extent of resection still one of the most consistent prognostic markers. Despite global molecular and genetic characterisation few candidate genes and pathways have been identified that could be used in a more targeted approach to therapy. The phosphoinositide 3-kinase (PI3K) pathway is one of the most commonly activated pathways in human cancer including glioma and medulloblastoma. PI3Ks transduce signals from growth factors and cytokines resulting if the phosphorylation and activation of the downstream effecter AKT. Signalling through AKT can induce changes in cell growth and proliferation, and apoptosis. We have analysed the status of the PI3K pathway in a cohort of ependymomas using immunohistochemistry for phospho-AKT. A tissue microarray containing 172 primary ependymomas and 61 recurrences was analysed. Positive results were obtained for 124 (72%) primary ependymomas and 49 recurrences (80%). Survival analysis identified a significant link between positive staining for phospho-AKT and a poorer event free survival using univariate (p = 0.05) and multivariate analysis (p = 0.03). We sequenced exon 9 and 20 of the PIK3CA gene, where activating mutations are commonly found, in 23 ependymomas. No mutations were identified. Using ependymoma SNP array data we found no copy number loss or loss of heterozygosity of the loci containing the PI3K pathway negative regulator PTEN. Analysis of methylation array data also identified no hypermethylation of the PTEN promoter. In conclusion we have identified PI3K pathway activation in a high percentage of ependymomas. If the pathway is proven to play a role in tumor pathogenesis it would provide a potential target for future therapies which would be effective in a large proportion of ependymomas.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-16. GAIN OF 1q25 PREDICTS POOR PROGRESSION-FREE SURVIVAL FOR PEDIATRIC INTRACRANIAL EPENDYMOMAS AND ENABLES PATIENT RISK STRATIFICATION: A EUROPEAN CLINICAL TRIAL COHORT ANALYSIS ON BEHALF OF CCLG, SFOP AND SIOP

John-Paul Kilday ¹, Biswaroop Mitra ¹, Caroline Domerg ², Jennifer Ward ¹, Felipe Andreiuolo ³, Teresa Osteso-Ibanez ¹, Audrey Mauguen ², Pascale Varlet ⁴, Marie-Cecile Le Deley ², James Lowe ⁵, David W Ellison ⁶, Richard J Gilbertson ⁷, Beth Coyle ¹, Jacques Grill ⁸, Richard G Grundy ¹

Abstract

INTRODUCTION: The high incidence of recurrence and unpredictable clinical outcome for pediatric ependymoma reflect the imprecision of current therapeutic staging and need for novel risk stratification markers. We therefore evaluated 1q25 copy number gain across three age and treatment defined European clinical trial cohorts of pediatric intracranial ependymoma. EXPERIMENTAL DESIGN: Frequency of 1q gain was initially assessed across 48 ependymomas (42 primary, 6 recurrent) using Affymetrix® 500K SNP arrays. Gain of 1q25 was then evaluated by interphase FISH across 189 tumors treated on the CCLG/SIOP CNS9204 (n = 60) and BBSFOP (n = 65) adjuvant chemotherapy trials, or with primary post-operative radiotherapy (SIOP CNS9904/RT, n = 64). Results were correlated with clinical, histological and survival data. RESULTS: Gain of 1q was the most frequent imbalance in primary (7/42, 17 %) and recurrent ependymomas (2/6, 33 %). Gain of 1q25 was an independent predictor of tumor progression across the pooled trial cohort (HR 2.55, 95 % CIs 1.56 - 4.16, p = 0.0002) and both CNS9204 (HR 4.03 (95 % CIs 1.88 - 8.63)) and BBSFOP (HR 3.10 (95 % CIs 1.22 - 7.86)) groups. The only clinical variable associated with adverse outcome was incomplete tumor resection. Integrating tumor resectability with 1q25 status enabled stratification of cases into disease progression risk groups for all three trial cohorts. INTERPRETATION: This is the first study to validate a prognostic genomic marker for childhood ependymoma across independent clinical trial groups. 1q25 gain predicts disease progression and can contribute to patient risk stratification. We advocate the prospective evaluation of 1q25 gain as an adverse marker in future international trials.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-17. THE ROLE OF LOCAL THERAPY IN RECURRENT EPENDYMOMA: A REPORT OF THE E-HIT-REZ-2005 STUDY

Gudrun Fleischhack ¹, Kristian Pajtler ¹, Martina Zimmermann ², Stefan Rutkowski ³, Monika Warmuth-Metz ⁴, Rolf-Dieter Kortmann ⁵, Torsten Pietsch ⁶, Andreas Faldum ⁷, Udo Bode ²

Abstract

BACKGROUND: Chemotherapy has limited efficacy in ependymomas. As local therapy is the most efficacious therapy in primary treatment, this analysis was set up to evaluate the local therapy and the outcome in patients with recurrent ependymomas treated in the German relapse study E-HIT-REZ-2005. METHODS: The E-HIT-REZ-2005 study is a non-randomized study consisting of an oral chemotherapy arm and a documentation arm (without study chemotherapy). In both arms local therapy as surgical resection and radiotherapy were administered where applicable as second-, third- or fourth-line treatment at the first or following relapses. RESULTS: Between 2006 and 2011 47 patients [median age 7.4 years (range 1.3-26.2 years), 38 WHO°III, 9 WHO°II] were enrolled into the study. At study entry 24 patients had an isolated local relapse and 23 patients had metastatic disease (4 M1, 7 M2, 12 M3). In the chemotherapy arm 36 patients were treated with an oral chemotherapy (temozolomide or trofosfamide + etoposide). At first relapse 28 patients underwent total (18), subtotal (8) or partial (2) resection of focal tumor lesions, 15 patients received radiotherapy (focal 15 and craniospinal 3). Local therapy after further progress/multiple relapses consisted of total, subtotal or partial resection in 7 patients and focal radiotherapy in 1 patient. The median follow-up was 22.6 months (range 1.3-57.4). So far 21 patients died from progressive disease, 10 patients are alive in CR, 1 patient in PR, 5 patients in SD, and 10 patients in PD. Overall survival was 32% at 4 years. It was not significantly influenced by age, sex, tumor site (infratentorial vs. supratentorial), and WHO grade (°III vs. °II) at primary diagnosis but was significantly shorter in metastastic vs. nonmetastatic relapses log rank, p < 0.001). CONCLUSIONS: Multimodal therapy, inclusively aggressive local therapy, led to long-term survival in one third of patients with a recurrent ependymoma. Metastatic disease is a poor prognostic factor.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-18. HYPOFRACTIONATED RADIOTHERAPY (RT) BOOST FOR CHILDREN WITH EPENDYMOMA AND A MEASURABLE RESIDUE AFTER SURGERY: RESULTS OF THE SECOND PROTOCOL OF THE ITALIAN ASSOCIATION OF PEDIATRIC HEMATOLOGY AND ONCOLOGY (AIEOP)

Lorenza Gandola ¹, Emilia Pecori ¹, Giovanni Scarzello ², Salvina Barra ³, Maurizio Mascarin ⁴, Silvia Scoccianti ⁵, Anna Mussano ⁶, Maria Luisa Garré ⁷, Sardi Jacopo ⁸, Paolo Pierani ⁹, Elisabetta Viscardi ¹⁰, Rita Balter ¹¹, Daniele Bertin ¹², Felice Giangaspero ¹³, Maura Massimino ¹

Abstract

To evaluate feasibility in a multicentric setting and clinical results of a RT boost for children with Ependymoma and measurable residual disease after first line or second look surgery. The second AIEOP protocol for childhood ependymoma opened in 2003. After centralized pathological review, children were stratified to receive: 1) 3D conformal RT, 59.4 Gy/33 fractions, to the tumor bed in case of complete resection and grade II tumor; 2) same RT followed by four cycles of VEC chemotherapy in case of complete resection and anaplastic ependymoma; 3) VECx4, second look surgery whenever feasible, local RT as in 1) followed by a stereotactic hypofractionated (8 Gy/2 fractions) boost to the residue still measurable after previous treatments. From 2003, 128 children entered the study. In 21 children (median age 4,5 years, 13 grade II, 17 infratentorial), out of 43 with residue after first surgery, second look wasn't feasible or incomplete and thus received VEC and 59.4 Gy to the tumor bed plus 8 Gy to the gross residue. 16 children are alive without progression at a median of 36 months (10-120 months) from diagnosis, 3 died of local progression at a median of 20 months, and 2 relapsed distantly 17-23 months from diagnosis. No iatrogenic death or major toxicity occurred. 4 children, irradiated with Tomotherapy, developed radiation related MRI changes regressing with steroids within 8 months. 6 years OS and PFS for the whole series were 76% and 63% respectively, PFS for children with and without residue after first surgery was 51% and 75% (P = 0.08) and local control 61% and 86% (P = 0.05) respectively. Hypofractionated RT boost was feasible and contributed to obtain local control in 18/21 children with measurable residue. An aggressive local treatment strategy, multiple surgeries and RT, is required to improve outcome in children with Ependymoma.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-19. PRECLINICAL EVALUATION OF BORTEZOMIB AND LAPATINIB IN PEDIATRIC EPENDYMOMA

Michael Pearlman ¹, Soumen Khatua ¹, Timothy Van Meter ², Dimpy Koul ¹, Al Yung ¹

Abstract

INTRODUCTION: Ependymomas are the third most common central nervous system (CNS) tumors in children. Surgery and radiation remains the cornerstone of management. They are relatively resistant to chemotherapy and recurrent or refractory tumors following surgery and radiation are a therapeutic challenge with a five-year survival of less than 60%. Lack of clinical models and identification of specific molecular pathways in these tumors has precluded drug testing and profiling targeted therapy. We report comprehensive drug testing on pediatric ependymoma cell lines. METHODS: Cell lines were directly established from 4 pediatric ependymoma tumors; both posterior fossa and supratentorial in origin. Each cell line was exposed to 10 different chemotherapeutic agents individually and in combination. These agents were selected from different libraries: antimetabolites, proteosome inhibitors, EGFR/HER-2 inhibitors, DNA synthesis/anti microtubule, TOPO-2 inhibitors and alkylating agents. Anti-tumor effect was evaluated using Cell Titer Blue (CTB) assays and dose-dependent growth inhibition over 96 hours was followed. Drug treatment for 96hrs resulted in a dose-dependent growth inhibition. RESULTS: The compounds tested showed a differential response in ependymoma cells. The proliferation of ependymoma cells was decreased in a concentration-dependent manner with most agents. Bortezomib a proteosame inhibitor and lapatinib, a VEGF/HER-2 inhibitor, were striking in their significant inhibition of ependymoma cell proliferation individually and in combination. Bortezomib's ED50 is between 0.5 and 1 nM. Lapatanib's ED50 is between 1 and 10 nM. In combination with each other there was a substantial additive effect. Additionally when either Lapatanib or Bortezomib was added to Temodar there was an additive effect. Their efficacy was independent of the original tumor location. CONCLUSION: Our study demonstrates that bortezomib and lapatinib individually and in combination inhibits growth of these tumors. These preliminary data provides better understanding of the tumor biology and therapeutic leads which need to be evaluated in prospective clinical trials.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-20. FEASIBILITY AND OUTCOME OF FRACTIONATED FULL COURSE REIRRADIATION USING IMRT IN CHILDREN WITH ANAPLASTIC EPENDYMOMA

Arnold Paulino ¹, Jack Su ², Robert Dauser ², William Whitehead ², Bin Teh ¹, Murali Chintagumpala ²

Abstract

BACKGROUND: Fractionated reirradiation to full doses is seldom done because of concerns of neurotoxicity. MATERIALS AND METHODS: We retrospectively reviewed our experience with full course reirradiation in locally recurrent ependymoma. We calculated the maximum (Dmax) and mean dose (Dmean) for surrounding normal structures. RESULTS: Seven children with intracranial anaplastic ependymoma underwent a 2nd course of fractionated radiotherapy (2XRT) for isolated locally recurrent ependymoma. Median age at initial fractionated radiotherapy (1XRT) was 6 years and at 2XRT was 9.7 years. All recurrences were in the high dose region of the 1XRT course. Prior to 2XRT, 6 patients had complete resection of recurrent tumor. Both 1XRT and 2XRT were delivered using intensity modulated radiation therapy (IMRT). The median time from end of 1XRT to beginning of 2XRT was 51 months (22-93 months). The median dose to the clinical target volume was 59.4Gy for 1XRT; for the 2XRT, all patients received 54Gy to the tumor bed with a 1 cm margin. The combined 1XRT and 2XRT median Dmax were: brainstem 77.8Gy (7.8-113.4Gy), optic chiasm 38Gy (6.6-55.8Gy), optic nerve 22.5Gy (3-53.1Gy), eye 11.8Gy (3.5-49.1Gy), lens 2.7Gy (1.1-6Gy) and spinal cord for infratentorial tumors 76.7Gy (69.3-103.8Gy). The combined median Dmean were: brainstem 50.9Gy (6.5-63Gy), optic chiasm 14.1Gy (3.4-4.8Gy), optic nerve 12.9Gy (1.2-47.4Gy), eye 4.2Gy (1.2-22.8Gy), lens 1.6Gy (0.4-2.4Gy) and spinal cord 12.9Gy (5-18.2Gy). The 2-year overall and progression-free survival was 85.7% and 71.4%. Three patients have failed at 3, 13 and 26 months after 2XRT; all had local recurrence with 1 concomitant leptomeningeal spread. With a median follow-up of 21 months after 2XRT, none of the patients had brain necrosis, myelitis or blindness. One patient had transient vasculitis 8 weeks after 2XRT which resulted in visual impairment but completely resolved on steroids. CONCLUSION: With the use of IMRT, full-course reirradiation in locally recurrent ependymoma is feasible.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-21. ANAPLASTIC EPENDYMOMA. RESULTS FROM POLISH PEDIATRIC NEUROONCOLOGY GROUP

Danuta Perek ¹, Monika Drogosiewicz ¹, Iwona Filipek ¹, Marta Perek Polnik ¹, Bozenna Dembowska Baginska ¹, Jacek Wachowiak ⁴, Bogna Kazmierczak ⁴, Grazyna Sobol ⁵, Katarzyna Musiol ⁵, Jerzy Kowalczyk ⁶, Hanna Wisniewska Slusarz ⁶, Jaroslaw Peregud-Pogorzelski ⁷, Wieslawa Grajkowska ², Marcin Roszkowski ³

Abstract

Optimal treatment of ependymoma remains controversial. Prognostic value of histological grade is also questioned. In our historical patients with anaplastic ependymoma (AE) treated with surgery and craniospinal radiotherapy survival was 32%. We have thus introduced a new treatment protocol. AIM: To present treatment results from this group of patients. MATERIAL AND METHODS: Between 2003-2011 40 patients aged 7 m-17.5 yrs /median5.5yrs were treated with this protocol (surgery, chemotherapy and focal radiotherapy (patients > 3 yrs). AE was defined when high mitotic activity (5-10/hpf), microvascular proliferation and foci of necrosis were present. There were 26 pts over and 14 under 3 yrs of age. 25 pts had infratentorial and 15 supratentorial tumors. Complete resection was performed in 17 pts, 23 had subtotal or partial resection. EFS and OS were assessed, correlated with age, localization, resection (assessed by neurosurgeon +/- MRI at 72 hrs). RESULTS: 36 out of 40 patients (11 <3yrs and 25 >3yrs of age) are alive with 5 yrs EFS and OS of 62% and 88%. Eleven of 14 pts<3yrs of age are alive, 10m-7yrs/5yrs from diagnosis. Twenty-five out of 26pts >3yrs of age are alive, 6m-8.5yrs /4yrs9m from diagnosis. All patients with supratentorial localization are alive 5m-8.5yrs/6yrs from diagnosis. Twenty-one out of 25 patients with infratentorial tumors are alive from 9m-8yrs4 m/3yrs4 m. All 17 patients with complete tumor resection are alive with 5 yrs EFS of 100 %. There was favorable correlation between EFS and supratentorial tumors (p-0,025), complete resection ( p < 0.001) and age over 3yrs ( p < 0.006) whereas age did not correlate with OS. CONCLUSIONS: Introduction of our protocol resulted in improved survival of children with AE. Excellent results in completely resected supratentorial AE indicate a change in the treatment strategy which we are now considering. Supported by The National Centre for Research and Development.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-22. PATTERNS OF DISSEMINATION IN MYXOPAPILLARY EPENDYMOMA -OPTIMIZING CURRENT RADIATION FIELDS

Wan-Yee Teo ¹, Murali Chintagumpala ¹, Fatih Okcu ¹, Robert Dauser ¹, Anita Mahajan ³, Adekunle Adesina ¹, William Whitehead ¹, Andrew Jea ¹, Robert Bollo ¹, Arnold C Paulino ²

Abstract

BACKGROUND: Myxopapillary ependymoma (MPE) accounts for 10-20% of pediatric intramedullary spinal cord tumors. Standard of care in children with MPE involves gross total resection with radiotherapy (RT) reserved for subtotal resection and recurrent tumors. To better understand what RT fields need to be treated in the setting of neuraxis dissemination in MPE, we investigated the patterns of dissemination in a pediatric series of MPE at our institution. Specifically, we were interested in whether craniospinal fields are needed at tumor dissemination. PATIENTS AND METHODS: Eight patients with MPE were seen from 1999-2009 at the Texas Children's Cancer Center. Median age was 13.6 years at initial diagnosis (range: 6.2-18.1 years). Tumor location was lumbar, sacral or both in all with thoracic involvement in 3 patients. Three of 8 patients had disseminated disease at initial presentation on MRI. Initial treatment was gross total resection (GTR) in 4 and subtotal resection (STR) followed by RT in 4. RT fields for the STR patients were partial spine fields including all radiographically visible tumors. RESULTS: At a median follow up of 3.2 years (range: 1-6.8 years), 3 patients progressed of which 1 died. Of 4 patients who had GTR only, 2 recurred and required RT. Of 4 patients who received STR with RT, 3 patients had stable disease while 1 relapsed. A review of the 3 recurrences revealed relapse at the initial tumor site in all patients, with 2 having disseminated disease either proximal or distal to the original site of disease. Patterns of dissemination analysis at initial presentation and at relapse reveal the absence of intracranial dissemination. CONCLUSION: Neuraxis dissemination is a common pattern of spread in MPE. However our institutional experience suggests that the pattern of dissemination in MPE does not involve the brain which can therefore be excluded from the radiation field.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-23. ANALYSIS OF CHROMOSOME 1Q GAIN AS GENETIC MARKER FOR RISK STRATIFICATION OF PEDIATRIC EPENDYMOMA PATIENTS - VALIDATION AS AN ADVERSE PROGNOSTIC MARKER IN THE GERMAN MULTICENTER HIT2000 TRIAL

Natalia Velez-Char ¹, Evelyn Doerner ¹, Anja zur Muehlen ¹, Valentina Vladimirova ¹, Monika Warmuth-Metz ³, Rolf Kortmann ⁴, Katja von Hoff ², Carsten Friedrich ², Stefan Rutkowski ², Andre O von Bueren ², Torsten Pietsch ¹

Abstract

In contrast to histopathological grading which varied in respect to its prognostic value between different clinical trials, extent of resection was found to be consistently associated to the clinical outcome. In retrospective series, gain of genetic material of chromosome arm 1q was identified to predict worse outcome. This marker was mainly assessed by FISH analysis which typically showed failure rates of 15-20 % in archival material. To validate this marker in a homogenously treated patient cohort, we analysed chromosome 1q in 138 consecutive cases enrolled into the multicenter trial HIT2000 (postoperative chemotherapy and irradiation, in a sequence depending on age and extent of resection) in which formalin-fixed, paraffin embedded material was available for DNA extraction. 88/137 ependymomas were located in the infratentorial region. 24 cases were diagnosed as WHO grade II ependymoma, 113 as anaplastic ependymoma (WHO grade III). By using multiplex ligation-dependent probe amplification (MLPA) for 5 markers located on chromosome 1q and control markers, we were able to analyse 137/138 cases (99 %) and found a gain of chromosome 1q in 21 cases (15.3 %). Interestingly, none of the 24 WHO grade II ependymomas had 1q gain. At a median follow-up of 3 years, patients with tumors showing 1q gain had a significantly lower 3-year overall survival (OS) (±SE) of 61% (± 13% compared to patients lacking this marker (90% (± 14%, p = 0.001). The distribution of this marker was similar when comparing patients with supra- and infratentorial tumors. Multivariable analysis demonstrated that gain of chromosome 1q was an independent risk factor for OS, and residual tumor for event-free survival, respectively. In conclusion, we validated chromosomal 1q gain to be a useful independent genetic marker for risk stratification of pediatric ependymoma patients which can be evaluated by MLPA representing a robust, reliable and cost-efficient method.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-24. TELOMERASE INHIBITION INDUCES GROWTH ARREST IN PAEDIATRIC EPENDYMOMA

Mark Barszczyk ¹, Pawel Buczkowicz ¹, Andrew Morrison ², Uri Tabori ², Cynthia Hawkins ²

Abstract

Ependymomas represent the third most common paediatric brain tumour, yet effective chemotherapeutics are lacking and 5-year survival rates remain poor at approximately 50%. Previous studies have shown that the majority of ependymomas possess telomerase, an enzyme that maintains telomere length and permits limitless growth potential. The objective of this study was to elucidate whether telomerase is an effective therapeutic target in ependymoma using the telomerase inhibitors MST-312 and Imetelstat. Paediatric ependymoma cell lines R254 and BXD-1425EPN were treated for 72 hours with MST-312 in parallel with telomerase-negative control cells. R254 ependymoma cells were also treated with Imetelstat for 17 weeks in parallel with mismatch control and untreated cells. Cell number, apoptosis (TUNEL), senescence (beta-galactosidase), telomerase activity (telomere repeat amplification protocol), cell cycle arrest (flow cytometry) and DNA damage (immunofluorescence (gammaH2AX)) was assessed following telomerase inhibition by either compound. MST-312 telomerase inhibition reduced proliferation by 50%, increased γH2AX associated DNA damage 2.2-fold and induced a marked increase in G2 cell populations in both R254 and BXD-1425EPN ependymoma cells but not in telomerase-deficient control cells. Imetelstat treatment of R254 ependymoma cells decreased proliferation after 6 weeks and induced growth arrest following 15 weeks of treatment while no effect was observed in mismatch control or untreated cells. The observed growth arrest was associated with an 80% increase in senescence and 20% decrease in viability. These findings suggest that telomerase inhibition may represent a potential therapeutic strategy for paediatric ependymoma.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-25. INCOMPLETE TUMOR RESECTION IN PATIENTS WITH PEDIATRIC EPENDYMOMA TREATED WITHIN THE HIT2000 TRIAL

Kara Krajewski ¹, Katja von Hoff ², Gertrud Kammler ¹, Carsten Friedrich ², André von Bueren ², Rolf-Dieter Kortmann ³, Juergen Krauss ⁴, Monika Warmuth-Metz ⁵, Stefan Rutkowski ²

Abstract

OBJECTIVE: Extent of resection is the strongest prognostic factor in intracranial pediatric ependymoma. In case of postoperative residual tumor (R+), second-look surgery is recommended whenever feasible. We analyzed the frequency and outcome of R+ ependymoma patients with and without second surgery. METHODS: Analysis of patients with localized ependymoma aged 0-21 years with central review of pre- and postoperative MRI imaging, who were treated within the multicenter HIT2000 study (patients < 4 years of age or R+ after 2005: primary chemotherapy followed by radiotherapy; otherwise: primary radiotherapy followed by chemotherapy if WHO III°) and operated before November 2010. RESULTS: 221 patients qualified for evaluation. Initial operations were performed in 70 centers. After surgery, 118 (53%) had complete tumor removal (R0) as determined by central neuroradiological reference, 66 (30%) were R + , and 37 were indeterminable (17%; mostly due to technical issues). Central and local neuroradiological assessments diverged in 24% of patients. R+ was found in 19/48 (40%) supratentorial hemispheric, 28/90 (31%) 4th ventricle/cerebellar, and 15/33 (45%) tumors in/with extension to the cerebellar-pontine angle (6: other location, 7: no data). In 40/66 available surgical reports, gross total resection was described in 11. Reasons for intentionally leaving residual tumor were: primary biopsy (9), localization (6), infiltration of cranial nerves (5) or arteries (2), bradycardia (2), adherent tumor capsules (2), and other (3). 24/66 patients with R+ underwent reoperation, 15 before and 9 after onset of adjuvant therapy. 3-year EFS for 10 patients who achieved R0 through reoperation was 88 % (± 12) vs. 41% (± 7) for R+ patients without second surgery or persisting R+ (p = 0.03). CONCLUSION: In this multicenter study, a high percentage of patients had residual tumor after primary surgery. Central neurosurgical reference is essential for standardized evaluation. Prognosis may be enhanced through consequent evaluation for reoperation. Supported by Deutsche Kinderkrebsstiftung

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-26. ANTI-TUMORAL EFFECT OF THE HDACi SAHA ON PEDIATRIC GLIAL TUMORS

Céline Ferreira ¹, Geoffrey Dieffenbach ¹, Carmela Barbosa ¹, Pascale Cuny ¹, Jacques Grill ²

Abstract

Ependymoma management remains challenging as there is currently no effective adjuvant therapy besides radiotherapy due to the high chemoresistance of these tumors. Recent studies have highlighted the interest of chromatin modulation using histone deacetylase inhibitors (HDACi) for cancer treatment. We studied the effect of an HDACi, SAHA, on both primary cell cultures isolated from surgical resection of ependymomas and high grade gliomas and a pediatric glioma cell line. Anti-proliferative effect of the compound was determined using MTS assay, induction of cell cycle changes was checked by flow cytometry prior to further protein analysis and in vivo experiments. SAHA exhibit a dose-dependant anti-proliferative effect on our various models, with IC50 of 1 µM for SF188 and around 2 µM for ependymoma cell cultures. Cell cycle analysis on SAHA treated-cells showed far greater sub-G1 population fraction although markers associated with apoptotic cell death were not displayed. We observed a high basal level of autophagy in our models, and treatment with SAHA leads to an increase in autophagic vesicles formation. To check whether autophagy could be a resistance mechanism to treatment or could participate to cell death, we inhibited autophagy using chloroquine while treating cells with SAHA. Compared to SAHA alone, this combination enhanced the anti-profliferative effect of SAHA on our in vitro models as well as its cytotoxic effect (increase in sub-G1 fraction). In a slow-growing ependymoma sub-cutaneous xenograft model, treatment with SAHA alone or in combination with chloroquine did not show a significant effect on tumor growth, but an increase in the sub-G1 cellular fraction was found in mice treated simultaneously with the two compounds. HDACi are potent drug candidates for glial tumors management. Further studies are needed to asses its efficiency in vivo and determine which combination could increase its anti-tumoral effects.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-27. FROM MOLECULAR HETEROGENEITY TO THERAPEUTIC TARGETS IN EPENDYMOMA

Elena Piccinin ¹, Maura Massimino ², Felice Giangaspero ³, Monica Brenca ¹, Erica Lorenzetto ¹, Iacopo Sardi ⁴, Lorenzo Genitori ⁴, Bianca Pollo ⁵, Daniel Bertin ⁶, Roberta Maestro ¹, Piergiorgio Modena ¹

Abstract

BACKGROUND:. Despite recent improvements in the definition of ependymoma-specific molecular profiles by high-throughput approaches, so far such information did not promote a rational strategy for innovative treatments combining targeted agents with conventional therapies. METHODS: We analyzed 15 ependymoma tumors, 6 ependymoma cell cultures and 5 control samples for expression and activation status of receptor kinases, their ligands, downstream intracellular kinases, as well as regulator microRNAs. Analyses at the protein level were performed by protein arrays and western blotting and at the RNA level by real-time quantitative PCR. Mutation detection at the DNA level was performed by sequencing and copy-number analyses. Pharmacologic treatments of cell cultures were evaluated by standard dose-response citotoxicity assays. RESULTS: Recurrent elevated expression and activation of ERBB1, -2 -4, IGF1R, IR, PDGFRB and EPHB2 were revealed in a variable fraction of cases ranging from 29% to 43%. In the absence of overt mutations, the expression of known ligands and miRNA modulators (EREG, IGF2, mir-375, mir-9) suggests the existence of autocrine/paracrine loops. With the exception of the pair ERBB1/2, recurrent co-activation events are rare. Multiple receptor kinases revealed activated expression in individual patients, including MER, TRKB, EPHA7, PDGFRA, MSPR, further supporting the described elevated molecular heterogeneity of ependymoma. In ependymoma cell cultures, response to EGFR small molecule inhibitor correlated with receptor expression level and activation status, and significantly augmented cell sensitivity to irradiation. Intracellular signaling was mediated by ERK1/2 and AKT activation, either individually or concomitantly. Concurrent elevated expression/activation of multiple molecules involved in stress response, inflammation and vascular signaling (p38alpha, CREB1, HSP27, TIE1/2, IL1A/B, LIF, mir-149) underscores the importance of these pathways, which remain poorly investigated in ependymoma. CONCLUSIONS: Despite the absence of recurrent genetic alterations that may drive targeted treatments in ependymoma, our combined approaches identified ERBB-, Insulin- and PDGFR- pathways as candidate therapeutic targets.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-28. PROTON RADIOTHERAPY FOR CHILDHOOD CNS EPENDYMOMA: CLINICAL OUTCOMES AND PATTERNS OF FAILURE FOR A COHORT OF 67 PATIENTS

Shannon MacDonald ¹, David Ebb ¹, Beverly Lavally ¹, Beow Yeap ¹, Karen Marcus ², Nancy Tarbell ¹, Torunn Yock ¹

Abstract

BACKGROUND/PURPOSE: Young age at diagnosis in combination with the proximity of critical CNS structures to target volumes for ependymoma makes protons an appealing modality for treatment. Clinical outcomes are needed to verify disease control and decreased toxicities. We report outcomes and patterns of failure for a cohort of 67 patients treated with involved field proton radiation. METHODS AND MATERIALS: Children with localized intracranial ependymoma treated at the Francis H. Burr Proton Facility and Harvard Cyclotron between November 2000 and February 2011 were included in this study. RESULTS: 67 patients were treated with involved field proton radiation. Median age at the time of diagnosis was 41 months (range 11 months - 20 years). 49 patients had infratentorial ependymoma and 18 had supratentorial ependymoma. 44 had a GTR while 23 had a STR. 31 patients had anaplastic histology; 36 had classic ependymoma. At a median follow-up of 36 months from the start date of radiation therapy among the 62 patients still alive, local control, progression free, and overall survival at 1 and 3 years were 97%/88%, 94%/75%, and 100%/93%, respectively. STR was significantly associated with poorer local control (90%/67% vs. 100%/96%, p = 0.002) and lower progression-free survival (86%/49% vs. 98%/85%, p = 0.004). Anaplastic histology was not associated with lower progression-free survival (97%/65% vs. 91%/81%, p = 0.358). Local control was 97%/80% among patients with anaplastic histology and was 97%/92% among those with classic ependymoma, though not significant (p = 0.498). Of the 17 patients that relapsed, 6 has isolated local failures, 2 patients had synchronous failures local and distal (spine and lateral ventricle), and 9 had isolated distant failures ( 5 spinal, 4 elsewhere in the brain). CONCLUSIONS: Disease control with proton therapy compares favorably to the literature. Although local in-field failures do occur, patterns of failure show that the majority of patients have failures distant from the primary site.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-29. PROGNOSTIC SERUM CYTOKINES IN PEDIATRIC EPENDYMOMA

Stephanie Schittone ¹, Andrew Donson ¹, Diane Birks ¹, Vladimir Amani ¹, Andrea Griesinger ¹, Michael Handler ³, Margaret Madey ², Thomas Merchant ², Nicholas Foreman ³

Abstract

BACKGROUND: Ependymoma recur in approximately 30% of children. A previous study by our group identified an immune gene expression signature in primary tumor samples that was associated with a favorable prognosis. Based on these findings, we hypothesized that specific serum cytokine levels would recapitulate this good prognosis immune signature in the periphery. APPROACH: Serum samples were obtained from a preliminary cohort of 21 pediatric ependymoma patients undergoing standard treatment (surgery and radiation) at the time of radiation and at subsequent time points (3 months; 1 year). A panel of 35 cytokines was screened in these samples using a multiplexed luminex bead platform. RESULTS: An initial analysis was performed to identify cytokine expression that was associated with outcome. The average level of 31 of the 35 cytokines was higher in patients who later suffered recurrence (n = 8) than those who did not (n = 13) (p < 0.0001). Despite this highly significant trend, no single cytokine was statistically significantly associated with outcome, the 4 most differentially expressed genes being MIP-1α, IL-1β, IL-1Rα and IL-2 (p < 0.15) that were associated with a worse prognosis. A second longitudinal analysis sought to determine whether changes in cytokine levels over the year post-radiation were associated with outcome. This revealed that CCL2 (p < 0.05) increased post-radiation in those patients who later recurred but decreased in those who did not. Conversely IL-12p40 (p < 0.05) decreased post-irradiation in those patients who later recurred and increased in those who did not. CONCLUSION: Contrary to our hypothesis, higher levels of cytokines were associated with recurrence in ependymoma. These data suggest that the immune status of periphery is not reflective of the immune status of the tumor microenvironment. Significant associations between outcome and changes in serum levels of specific cytokines in this preliminary study are being validated in a larger cohort of pediatric ependymoma samples (n = 99).

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-30. TREATMENT OF CHILDHOOD INTRACRANIAL EPENDYMOMA WITH SURGERY ALONE AT DIAGNOSIS: THE CANADIAN PEDIATRIC BRAIN TUMOUR CONSORTIUM EXPERIENCE

Juliette Hukin ¹, Tamir Ailon ², Chris Dunham ¹, Anne-Sophie Carret ¹², Uri Tabori ⁴, P Daniel McNeely ⁵, Shayna Zelcer ⁶, Beverley Wilson ⁷, Lucie Lafay-Cousin ⁸, Donna Johnston ⁹, David Eisenstat ¹⁰, Marianna Silva ¹¹, Nada Jabado ³, Stephen Yip ², Karen Goddard ¹³, Christopher Fryer ¹, Glenda Hendson ¹, Cynthia Hawkins ⁴, Sandra Dunn ¹, Ash Singhal ¹

Abstract

BACKGROUND: Gross total resection (GTR) improves survival, but deferral of radiotherapy to the developing brain in ependymoma is controversial. There is a paucity of data on such a strategy. This study reports on a group of children initially treated with GTR alone. METHODS: We conducted a multicenter, retrospective review of children (<18 years old) diagnosed with ependymoma in 12/16 participating Canadian centers. Inclusion criteria: GTR and no adjuvant therapy. Exclusion criteria: ependymoblastoma or mixed pathology. Pathology was centrally reviewed and immunostaining for EGFR was performed. RESULTS: A total of 201 patients with intracranial ependymoma were identified: 150 had posterior fossa ependymoma (PFE); 51 had supratentorial ependymoma (STE). 32 patients were treated with GTR alone upfront: 18 PFE; 14 STE. Staging was only performed in 18/32, all of which were negative for metastatic disease. 5 yr PFS and OS were 48%; and 68%; no significant difference was observed between PFE and STE (p = 0.70). Relapses occurred in 9/18 (50%) PFE and 8/14 (57.1%) STE; all but 2 relapses occurred within 2 yrs; 5/9 PFE relapses had dissemination whereas only 1/8 STE relapses had dissemination. 4 PFE and 3 STE were salvaged with resection and adjuvant therapy. Survival was inferior for patients < 3 yo at diagnosis for both groups (p < 0.035). Negative EGFR stain and WHO grade 2 had a trend toward improved survival but failed to reach significance. CONCLUSIONS: Treatment of intracranial ependymoma with GTR alone is a reasonable strategy in selected patients. Relapses occur at the primary site in STE but there is 50% risk of dissemination in PFE. Successful salvage occurs in both PFE and STE. Survival is inferior for infants. Identifying which ependymomas can be successfully treated in this fashion is essential. Identifying a specific molecular signature is imperative towards developing new therapies.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-31. ADVANCED PHOTON RADIOTHERAPY TECHNIQUES COMPARED TO PROTON TREATMENT FOR SMALL TARGETS, A DOSE PLANNING STUDY IN A RECURRENT CHILDHOOD EPENDYMOMA

Yasmin Lassen-Ramshad ¹, Anne Vestergaard ², Klaus Seiersen ², Henrik Pagh Schultz ¹, Morten Hoeyer ¹, Joergen B Petersen ²

Abstract

PURPOSE: Proton therapy is often considered superior to photon therapy due to favourable depth-dose characteristics, especially in radiotherapy of childhood cancers. We performed a dosimetric case study in a small target to compare advanced photon techniques, stereotactic radiotherapy (SRT) and volumetric arc therapy (VMAT) to intensity modulated proton therapy (IMPT) technique. METHODS: A treatment planning study was performed on a small recurrence of a grade III childhood ependymoma (0.8 cm in diameter) close to the brainstem. The enhancing tumour was defined as the clinical target volume (CTV). A dose of 20 Gy in 10 fractions was planned with the three techniques using setup margins of 2, 3, 4 and 5 mm on an eclipse dose planning system (Varian Medical Systems, Palo Alto, CA). RESULTS: Target coverage and dose to the brainstem were comparable for the three techniques. Mean dose to normal brain tissue for the 2mm margin was 0.78, 0.61 and 0.55 Gy for SRT, VMAT and IMPT, respectively, whereas the low dose volume receiving 5 Gy was 28, 36 and 25 ccm. The same tendency was observed for the other margin sizes. In clinical practice, image guided photon therapy is delivered using 2-3 mm margins, whereas proton therapy should be delivered with 4-5 mm margins, because of range uncertainties and the larger penumbra of protons. With these margins applied, the mean dose to the normal brain tissue was 0.78, 0.61 and 0.63 Gy for SRT(2mm), VMAT(2mm) and IMPT(4mm), respectively, whereas the low dose volume receiving 5 Gy was 28, 36 and 30.5 ccm for SRT(2mm), VMAT(2mm) and IMPT(4mm). CONCLUSION: For small targets the advantage regarding dose to the surrounding normal tissue could be vanishing for proton therapy compared with advanced photon therapy techniques.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-32. EPENDYMOMA-ANGIOGENESIS: PLATELET DERIVED GROWTH FACTOR RECEPTORS OVER-EXPRESSION HAS PROGNOSTIC SIGNIFICANCE

Lucas Moreno ¹, Sergey Popov ², Alexa Jury ², Safa Al Sarraj ³, Chris Jones ², Stergios Zacharoulis ¹

Abstract

Although vascular proliferation is commonly seen in ependymomas, relatively little is known about the angiogenic profile of these tumors. The platelet derived growth factor (PDGF) pathway is well established to be involved in glial tumorigenesis, and tumor-angiogenesis however it has not been examined extensively in ependymoma. Similarly little is known about the expression and its significance of key angiogenic factors such CD105, Vascular endothelial growth factor ( VEGF) and its receptors, c-kit and in ependymoma. We aimed to screen ependymomas for the expression status of various angiogenic factors and investigate their prognostic significance. Tissue samples were obtained from 24 patients treated at our institution with the diagnosis of ependymoma from 1991 to 2009, with IRB approval. Clinicopathological characteristics and outcome of these patients were recorded. Intensity of staining was scored semi-quantitatively in a blinded manner as either ‘moderate/high' or ‘low/no expression by one pathologist (SP). Pericyte coverage index (PCI) was calculated as the ratio SMA/CD34. The PCI was evaluated and average ± SD was 91.1% ±12.7. PDGFR-α and b were found to be over-expressed in the ependymoma tumor cells in 29.2% of the patients and PDGFR-b was over-expressed in 50% of the patients. High expression of PGDFR-α in tumor cells and tumor endothelial cells correlated with PFS: 2-year PFS was 16.7 ± 15.2 for those cases that showed overexpression of PDGFR-α in the tumor vs. 74.5 ±15.2 for those with low/no expression (p < 0.001). Additionally, 2-year PFS was 33.3 ± 19.2 for those with overexpression of PDGFR-α in the tumor-endothelium vs. 69.7 ± 11.4 for those with low/no expression (p = 0.018). High expression of PGDFR-β in tumour cells and tumor endothelial cells correlated with PFS: (2-year PFS 14.3 ± 13.2 vs. 79.5 ± 10.7 (p < 0.001). Multivariate analysis confirmed the prognostic significance of PDGFR-α. In conclusion PDGFRs might represent a target that requires prospective validation in ependymoma.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-33. mTOR AND MAP KINASE SIGNALING IN CHILDHOOD EPENDYMOMA OF THE POSTERIOR FOSSA - A POTENTIAL NEW THERAPEUTIC INTERVENTION

Daniel Bowers ¹, Lynn Gargan ¹, C J Horton ¹, Dinesh Rakheja ¹, Linda Margraf ¹

Abstract

BACKGROUND: Little is known regarding activation of the MAP kinase and mTOR pathways in childhood ependymomas. METHODS: 21 pediatric, posterior fossa ependymomas (23.8% females; mean age = 5.35 ± 5.72 years (range: 0.45 - 17.18 years) were examined for immunohistochemical expression of phosphorylated (Ser235/236) S6 ribosomal protein, a marker of mTOR complex1 activation; cyclin D1, a member of the cyclin protein family that is involved in regulating cell cycle progression; and Phospho-p44/42 MAPK (Erk1/2) (Thr202/Tyr204), a biomarker of MAP Kinase pathway activation. Primary cell lines derived from five pediatric ependymomas, including three tumors which were positive for S6, were exposed to therapeutic range concentrations of rapamycin; cell viability was examined by manual cell counts after staining with the vital dye trypan blue and compared established controls. Finally, two patients with multiply recurrent ependymomas who were treated with daily rapamycin are described. RESULTS: Immunohistochemistry studies were as follows: pS6 showed cytoplasmic reactivity (>10% of tumor cells) in 19/21 (90%) of cases, pERK staining mirrored pS6 in distribution but was more abundant and was present in 20/21 (95%) of cases. Cyclin D1 showed nuclear staining in 16/21 (76%) cases. Tumor cell line cell viability at 48 hours was reduced by 65-85% in the three pS6-positive tumor cell lines exposed to 15-20 ng/ml rapamycin compared to 50% reduction in viable cells in the control HEK-293T/17 cell line and 40% reduction in the two pS6-negative cell lines exposed to the same concentrations of rapamycin. Two patients with multiply recurrent ependymomas had near-complete tumor responses to daily rapamycin (18 months) or daily rapamycin + oral etoposide (12+ months). CONCLUSIONS: mTOR pathway signaling and the MAP kinase pathway may play a role in childhood ependymoma biology. Further investigation of potential biomarkers and targets of these pathways is warranted to improve therapy for children with ependymomas.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-34. PEDIATRIC EPENDYMOMAS HAVE INCREASED EXPRESSION OF GLIOMA-ASSOCIATED ANTIGENS (GAAS): IMPLICATIONS FOR VACCINE THERAPY

Jacky Yeung ¹, Ronald Hamilton ¹, Hideho Okada ¹, Regina Jakacki ², Ian Pollack ²

Abstract

BACKGROUND: Despite surgery and radiotherapy, as many as 50% of children with ependymomas will suffer from tumor recurrences that will ultimately lead to death. New treatment modalities are urgently needed. METHODS: We investigated the protein expression of three GAAs that are the targets of an existing vaccine for low- and high-grade gliomas. Immunohistochemistry was performed using antibodies specific for EphA2 (1:100), IL13Ralpha2 (1:1000), and Survivin (1:200). Cases included 1 WHO grade I (myxopapillary), 3 WHO grade II, and 5 WHO Grade III (anaplastic) ependymomas. Paraffin-embedded tissues were deparaffinized using xylene and serial ethanol washes. Antigen retrieval was performed using citrate buffer in a pressure cooker. After blocking, primary antibodies directed at each GAA were incubated overnight at 4°C. Negative controls were established by omitting the primary antibodies. Staining was visualized by HRP-conjugated secondary antibodies and DAB chromogen. Normal brain and ependyma were used for background staining controls. RESULTS: All ependymomas stained more strongly for all three GAAs than normal brain tissue or normal ependyma. Non-neoplastic tissues within and around the tumors also did not stain. Negative controls showed no staining. Most ependymomas showed diffuse staining, but in some there was patchy variability in intensity: EphA2 (2/9), IL13Ralpha2 (2/9), and Survivin (3/9). There was more variability in overall staining intensity for IL13Ralpha2 and Survivin than for EphA2 among the cases. Nuclear expression of survivin was decreased in grade 2 and 3 ependymomas compared to the single myxopapillary case. CONCLUSION: Pediatric ependymomas overexpress EphA2, IL13Ralpha2, and Survivin compared to normal brain. This provides the basis for the utilization of an established GAA-based glioma vaccine for pediatric ependymoma in a clinical trial setting.

Neuro Oncol. 2012 Jun;14(Suppl 1):i33–i42.

EM-35. RECURRENT ANAPLASTIC EPENDYMOMA WITH EXTRACRANIAL METASTASES - TREATMENT WITH SURGERY, RADIATION AND ORAL CHEMOTHERAPY

Adam Fleming ¹, Nada Jabado ¹, Christine Saint-Martin ¹, Carolyn Freeman ¹, Steffen Albrecht ¹, Jose-Luis Montes ¹

Abstract

INTRODUCTION: Intracranial ependymoma represents approximately 8% of pediatric brain tumours. Anaplastic ependymoma (WHO Grade III) is usually considered to have a more aggressive clinical course. Metastatic disease to locations outside the CNS has been reported, but is extremely rare. We describe a patient treated for supratentorial ependymoma with surgery and radiation, with multiple local recurrences and extracranial metastatic disease in her neck and mediastinum. CASE REPORT: A previously healthy girl presented at the age of 13 with new seizures. Neuro-imaging revealed a large supratentorial mass growing in the left cerebral hemisphere. The patient underwent gross total resection and received focal radiation to a dose of 59.4 Gy. One year later, she had disease recurrence on surveillance MRI at the original site. She had another gross total resection and was treated with stereotactic radiosurgery to a dose of 18 Gy. After another year she presented a recurrent nodule in the tumour bed, which was unresectable due to its proximity to the sagittal sinus. She was treated with another round of radiosurgery (18 Gy). She tolerated this well and her disease remained stable for another year. She then presented with local recurrence and cervical lymphadenopathy; biopsy proved this to be anaplastic ependymoma. She also had a mass lesion in her mediastinal area. She received a third dose of radiosurgery to the inital tumour bed, as well as radiation (35 Gy) to the neck. She was started on oral chemotherapy (temozolomide and etoposide). One year later she received 30 Gy to treat her progressive mediastinal disease, and then was changed to oral metronomic chemotherapy. She has remained on this regimen, and is doing well with stable disease and a good quality of life. SUMMARY: Extracranial metastatic ependymoma is rare, and treatment options poorly defined. This case reviews a multi-modality approach and oral chemotherapy options for this disease.

PERMALINK

EPENDYMOMA

EM-01. POST-OPERATIVE RADIOTHERAPY FOR FOURTH VENTRICLE EPENDYMOMA IN CHILDREN BELOW 3 YEARS OLD: GOOD PRELIMINARY RESULTS

Mohamed Zaghloul

Mohamed Elbeltagy

Amr Mousa

Eman Eldebawy

Amr Amin

Abstract

EM-02. ANAPLASTIC EPENDYMOMA AND DIFFUSE ASTROCYTOMA PRESENTING AS SYNCHRONOUS PRIMARY BRAIN TUMORS IN A CHILD (CASE REPORT)

Zdenek Pavelka

Vladimira Vranova

Iveta Valaskova

Lenka Tomasikova

Alexandra Oltova

Jiri Ventruba

Zdenek Mackerle

Leos Kren

Jarmila Skotakova

Karel Zitterbart

Jaroslav Sterba

Abstract

EM-03. THE NOVEL HUMAN HIGH-RISK EPENDYMOMA STEM CELL MODEL DKFZ-EP1NS REVEALS THE DIFFERENTIATION-INDUCING POTENTIAL OF TREATMENT WITH THE HISTONE DEACETYLASE INHIBITOR VORINOSTAT

Till Milde

Susanne Kleber

Andrey Korshunov

Hendrik Witt

Thomas Hielscher

Philipp Koch

Hans-Georg Koch

Manfred Jugold

Hedwig E Deubzer

Ina Oehme

Marco Lodrini

Hermann-Josef Gröne

Axel Benner

Oliver Brüstle

Richard J Gilbertson

Andreas von Deimling

Andreas E Kulozik

Stefan M Pfister

Martin-Villalba Ana

Olaf Witt

Abstract

EM-04. NESTIN PROTEIN EXPRESSION IS AN INDEPENDENT PROGNOSTIC MARKER IN EPENDYMOMA AND DISCRIMINATES WHO II EPENDYMOMA WITH POOR OUTCOME

Till Milde

Thomas Hielscher

Hendrik Witt

Marcel Kool

Stephen C Mack

Hedwig E Deubzer

Ina Oehme

Marco Lodrini

Axel Benner

Michael D Taylor

Andreas von Deimling

Andreas E Kulozik

Stefan M Pfister

Olaf Witt

Andrey Korshunov

Abstract

EM-05. CERVICAL LYMPH NODES DISSEMINATION OF A RECURRENT SUPRATENTORIAL EPENDYMOMA

Fanny Fouyssac

Emmanuelle Schmitt

Ludovic Mansuy

Jean-Claude Marchal

Laurent Coffinet

Valerie Bernier

Pascal Chastagner

Abstract

EM-06. PRIMARY SPINAL CORD EPENDYMOMA: A MULTI-INSTITUTIONAL EUROPEAN SERIES OF 54 PATIENTS

Daniela Sperl

Stergios Zacharoulis

Maura Massimino

Elisabetta Schiavello

Barry Pizer

Caroline Piette

Lidija Kitanovski

Katja von Hoff

Franz Quehenberger