Role of Radiotherapy in Supratentorial Primitive Neuroectodermal Tumor in Young Children: Results of the German HIT-SKK87 and HIT-SKK92 Trials

Radiation Therapy Plays an Important Role in the Treatment of Atypical Teratoid/Rhabdoid Tumors: Analysis of the EU-RHAB Cohorts and Their Precursors

PURPOSE

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare malignancy of the central nervous system in young children with a dismal prognosis. Prognostic markers have been extensively investigated but have not been validated. The role of radiation therapy (RT) remains controversial. We evaluated the impact of RT as part of multimodality treatment by analyzing data of a European AT/RT cohort.

METHODS AND MATERIALS

We retrospectively analyzed data of the European Registry for Rhabdoid Tumors and its precursors. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Potential impact of prognostic factors was analyzed using univariable and multivariable Cox regression analyses with RT as a time-dependent factor.

RESULTS

Data of 186 children (118 male, 68 female) treated from 1990 to 2016 were evaluable. The median age at diagnosis was 1.57 years (range, 0.01-26.70 years); 47% (87/186) of the patients were under the age of 18 months. Sixty-nine percent (128/186) received RT (focal RT, n = 93; craniospinal treatment with local boost, n = 34; spinal irradiation, n = 1). The median follow-up duration of the entire cohort was 1.73 years (range, 0.06-20.11 years). The estimated PFS and OS rates were 48% (95% CI, 41%-55%) and 72% (95% CI, 65%-78%) at 1 year and 33% (95% CI, 26%-40%) and 49% (95% CI, 41%-56%) at 2 years, respectively. On multivariable analysis, RT was an independent significant prognostic factor for PFS (hazard ratio, 0.45; 95% CI, 0.27-0.75; P = .002) and OS (hazard ratio, 0.54; 95% CI, 0.32-0.93; P = .025).

CONCLUSIONS

This analysis confirms the relevance of local therapies. RT was an independent prognostic factor for outcomes in children experiencing AT/RT. However, long-term sequelae have to be carefully evaluated and considered given the young age at time of RT.

Therapeutic implications of improved molecular diagnostics for rare CNS-embryonal tumor entities: results of an international, retrospective study

BACKGROUND

Only few data are available on treatment-associated behavior of distinct rare CNS-embryonal tumor entities previously treated as "CNS-primitive neuroectodermal tumors" (CNS-PNET). Respective data on specific entities, including CNS neuroblastoma, FOXR2 activated (CNS NB-FOXR2), and embryonal tumor with multi-layered rosettes (ETMR) are needed for development of differentiated treatment strategies.

METHODS

Within this retrospective, international study, tumor samples of clinically well-annotated patients with the original diagnosis of CNS-PNET were analyzed using DNA methylation arrays (n=307). Additional cases (n=66) with DNA methylation pattern of CNS NB-FOXR2 were included irrespective of initial histological diagnosis. Pooled clinical data (n=292) were descriptively analyzed.

RESULTS

DNA methylation profiling of "CNS-PNET" classified 58(19%) cases as ETMR, 57(19%) as HGG, 36(12%) as CNS NB-FOXR2, and 89(29%) cases were classified into 18 other entities. Sixty-seven (22%) cases did not show DNA methylation patterns similar to established CNS tumor reference classes. Best treatment results were achieved for CNS NB-FOXR2 patients (5-year PFS: 63%±7%, OS: 85%±5%, n=63), with 35/42 progression-free survivors after upfront craniospinal irradiation (CSI) and chemotherapy. The worst outcome was seen for ETMR and HGG patients with 5-year PFS of 18%±6% and 22%±7%, and 5-year OS of 24%±6% and 25%±7%, respectively.

CONCLUSION

The historically reported poor outcome of CNS-PNET patients becomes highly variable when tumors are molecularly classified based on DNA methylation profiling. Patients with CNS NB-FOXR2 responded well to current treatments and a standard-risk-CSI based regimen may be prospectively evaluated. The poor outcome of ETMR across applied treatment strategies substantiates the necessity for evaluation of novel treatments.

Treatment of Embryonal Tumours with Multilayered Rosettes with Carboplatin/Etoposide Induction and High-dose Chemotherapy within the Prospective P-HIT Trial

BACKGROUND

Embryonal tumours with multilayered rosettes (ETMR) are highly aggressive tumours occurring in early childhood. Published clinical data refer to retrospective, heterogeneously treated cohorts. Here, we describe the outcome of patients treated according to the prospective P-HIT trial and subsequent HIT2000-interim-registry.

PATIENTS AND METHODS

Age-stratified treatment included carboplatin/etoposide-induction, tandem-high-dose chemotherapy ("CARBO/ETO+HDCT") and response-stratified radiotherapy. Patients with centrally reviewed neuropathological and molecularly confirmed diagnosis of ETMR recruited within the P-HIT trial (2001-2011; n=19), the HIT2000-interim-registry (2012-2014; n=12) and earlier HIT-trials (n=4) were selected for analysis.

RESULTS

Age-adjusted incidence rate was 1.35 per 1 million children (aged 1-4 years) in the years 2012-2014. Median age at diagnosis for 35 patients was 2.9 years. Metastases at diagnosis were detected in 9 patients. One patient died due to postoperative complications. For 30 patients with non-brainstem tumour location, 5-year progression-free (PFS) and overall survival (OS) were 35% and 47% after treatment with CARBO/ETO+HDCT (n=17), compared to 0% and 8% with other treatments (n=13, p[OS]=0.011). All 4 patients with brainstem tumour died within 10 months after diagnosis. By multivariable analysis, supratentorial location: (HR[PFS]:0.07 [95%CI:0.01-0.38], p=0.003), localised disease (M0): (HR[OS] M0, no residual tumor:0.30 [95%CI:0.009-1.09], p=0.068; M0, residual tumor:0.18 [95%CI: 0.04-0.76], p=0.020) and CARBO/ETO+HDCT treatment (HR[OS]:0.16 [95%CI:0.05-054], p=0.003) were identified as independent prognostic factors. Of 9 survivors, 6 were treated with radiotherapy (craniospinal 4; local 2).

CONCLUSIONS

Our data indicate improved survival with intensified chemotherapy (CARBO/ETO+HDCT). However, despite intensive treatment, the outcome was poor. Thus, innovative therapies need to be evaluated urgently in an upfront setting.

C19MC amplification and expression of Lin28A and Olig2 in the classification of embryonal tumors of the central nervous system: A 14-year retrospective study from a tertiary care center

INTRODUCTION

CNS embryonal tumors (CET) other than medulloblastomas (MB) and atypical teratoid/rhabdoid tumors (AT/RTs), previously designated as 'central nervous system primitive neuroectodermal tumors' ('CNS PNETs'), are a heterogenous subset of tumors with poorly defined diagnostic criteria. Other than the subset of embryonal tumor with multilayered rosettes (ETMR) defined by C19MC amplification, most CETs are diagnosed by exclusion of other molecularly defined entities and histological mimics including MB, AT/RTs, and high-grade gliomas, and termed as CET, not otherwise specified (NOS) in the 2016 WHO classification.

AIM

To reclassify 'CNS PNETs' as per WHO 2016, and estimate the true proportion of CET, NOS in a tertiary healthcare setting, and to evaluate the diagnostic utility of C19MC amplification, Lin28A and Olig2 expression in the subclassification of CETs.

METHODS

Previously diagnosed cases of 'CNS PNETs' (2002-2016) were first evaluated by immunohistochemistry (IHC) for MIC2, RelaA, L1CAM, IDH1R132H, H3K27M, H3G34R, H3G34V, INI1, and BRG1 proteins and by fluorescence in-situ hybridization (FISH) for EWSR1 translocation to exclude histological mimics. The selected CETs (case cohort) and 79 histological mimics (comparison cohort) comprising of MB, AT/RT, pineal parenchymal tumors, Ewing sarcoma, esthesioneuroblastoma, intraocular medulloepithelioma, and H3G34R mutant high-grade glioma were subject to IHC for Olig2 and Lin28A, and FISH for C19MC amplification.

RESULTS

Twenty-two cases of 'CNS PNETs' were retrieved, all of which were negative for the first panel of markers and showed retained INI-1/BRG1 expression. Three of them (3/22, 13.6%) showed C19MC amplification (ETMR, C19MC-altered) with ETMR histology, Lin28A positivity, and Olig2 negativity. Among the remaining 19 CETs, one showed medulloepithelioma histology (Medulloepithelioma, NOS) and remaining were non-descript small round cell tumors (CET, NOS), all negative for Lin28A. Olig2 was positive in only 3 CETs (13.6%), all being CET, NOS. All tumors in the comparison cohort were negative for C19MC amplification, Lin28A and Olig2 except for 27% of ATRTs that were Lin28A positive.

CONCLUSION

ETMR, C19MC-altered constitute less than 14% of CETs, with majority remaining uncharacterized as CET, NOS. Lin28A is 100% sensitive for the detection of C19MC amplification; however, its specificity is limited by its expression in ATRTs. Olig2 expression is seen only in a small subset of CET, NOS and is of limited diagnostic utility.

Pineoblastoma segregates into molecular sub-groups with distinct clinico-pathologic features: a Rare Brain Tumor Consortium registry study

Pineoblastomas (PBs) are rare, aggressive pediatric brain tumors of the pineal gland with modest overall survival despite intensive therapy. We sought to define the clinical and molecular spectra of PB to inform new treatment approaches for this orphan cancer. Tumor, blood, and clinical data from 91 patients with PB or supratentorial primitive neuroectodermal tumor (sPNETs/CNS-PNETs), and 2 pineal parenchymal tumors of intermediate differentiation (PPTIDs) were collected from 29 centres in the Rare Brain Tumor Consortium. We used global DNA methylation profiling to define a core group of PB from 72/93 cases, which were delineated into five molecular sub-groups. Copy number, whole exome and targeted sequencing, and miRNA expression analyses were used to evaluate the clinico-pathologic significance of each sub-group. Tumors designated as group 1 and 2 almost exclusively exhibited deleterious homozygous loss-of-function alterations in miRNA biogenesis genes (DICER1, DROSHA, and DGCR8) in 62 and 100% of group 1 and 2 tumors, respectively. Recurrent alterations of the oncogenic MYC-miR-17/92-RB1 pathway were observed in the RB and MYC sub-group, respectively, characterized by RB1 loss with gain of miR-17/92, and recurrent gain or amplification of MYC. PB sub-groups exhibited distinct clinical features: group 1-3 arose in older children (median ages 5.2-14.0 years) and had intermediate to excellent survival (5-year OS of 68.0-100%), while Group RB and MYC PB patients were much younger (median age 1.3-1.4 years) with dismal survival (5-year OS 37.5% and 28.6%, respectively). We identified age < 3 years at diagnosis, metastatic disease, omission of upfront radiation, and chr 16q loss as significant negative prognostic factors across all PBs. Our findings demonstrate that PB exhibits substantial molecular heterogeneity with sub-group-associated clinical phenotypes and survival. In addition to revealing novel biology and therapeutics, molecular sub-grouping of PB can be exploited to reduce treatment intensity for patients with favorable biology tumors.

Survival of infants ≤24 months of age with brain tumors: A population-based study using the SEER database

INTRODUCTION

Brain tumors are the most common solid malignancy and leading cause of cancer-related deaths in infants. Current epidemiological data is limited by low numbers of reported cases. This study used a population-based approach with analysis of contemporary and historical survival curves to provide up-to-date prognostication.

METHODS

Observational cohort analysis was performed using the Surveillance, Epidemiology and End Results (SEER) database. Infants with brain tumors diagnosed from 1973 to 2013 were categorized by the most common tumor types (diffuse astrocytic and oligodendroglioma, choroid plexus, embryonal, ependymal, medulloblastoma and pilocytic astrocytoma). The 1, 5 and 10 year survival was stratified by decade, with trends in management and outcomes analyzed.

RESULTS

We identified 2996 affected infants satisfying inclusion criteria. All tumor types, except embryonal and choroid plexus, demonstrated improving survival with time. Infants with embryonal tumors showed a decline in survival from the 1970s to 1990s (p = 0.009), whereas infants with choroid plexus tumors had no change in survival. Infants with ependymal tumors experienced the greatest improvement in survival from 1980s to 1990s and 1990s to 2000s (p = 0.0001, p = 0.01), with 5-year survival probability improving from 28% (95% CI 15-42%) in the 1980s to 77% (95% CI 69-83%) the 2000s. The use of radiation declined from 1970 to 2000 for all tumors; however, radiation treatment for embryonal and ependymal subtypes increased after 2000.

CONCLUSIONS

While overall survival for infants with brain tumors has improved from the 1970s onwards, not every tumor type has seen a statistically significant change. Given changes in management and survival, prognostication of infants with brain tumor should be updated.

Feasibility of high-dose chemotherapy protocols to treat infants with malignant central nervous system tumors: Experience from a middle-income country

BACKGROUND

Results of high-dose chemotherapy (HDCT) protocols for the management of malignant central nervous system (CNS) tumors in infants are mostly reported in high-income countries. We evaluated the feasibility and results of such protocols in a middle-income country (Jordan).

METHODS

A retrospective study of infants' charts with CNS tumors between 2006 and 2015 who were treated according to HeadStart (HS) protocols. Data included patients' demographics, chemotherapy complications, and cost.

RESULTS

We identified 18 patients with median age 29 months (range, 9-62 months) at diagnosis (12 HS-I and six HS-II). Distribution according to pathology was: atypical teratoid rhabdoid tumors (ATRT) (nine), primitive neuoroectodermal tumors (PNET)/pineoblastoma (five), and medulloblastoma (four). Six patients (33%) had metastatic disease, and 14 (78%) had an incomplete resection. Eleven patients achieved partial or complete remission, two stabilized, and five progressed. Ten patients did not proceed to HDCT due to progression (five), financial reasons (two), failure to collect stem cells (one), and undocumented reasons (two). Seventy-eight chemotherapy cycles were administered (median interval 26 days). Main complications during induction and consolidation were febrile neutropenia (73% and 100%), documented infections (8% and 13%), and mucositis (12% and 88%), respectively. Three patients developed moderate hearing loss. No protocol-related mortality was reported. At the last follow-up, five patients were alive: three with medulloblastoma (19, 29, and 89 months) and two with ATRT (18 and 42 months). Three survivors received focal/craniospinal radiation. The median cost of a complete HS protocol, excluding surgery/radiotherapy, was $103 500 per patient; 39% of the median cost was related to pharmacy expenses.

CONCLUSIONS

These protocols were manageable in our context of limited health care resources. However, considering the significant costs and the modest survival rate, better selection criteria need to be used to identify patients likely to benefit from this approach.

Prognosis of Pediatric Patients with Pineoblastoma: A SEER Analysis 1990-2013

BACKGROUND

Pineoblastomas are rare, malignant embryonal tumors that have a relatively higher incidence and a poorer prognosis in children. Owing to the rarity of these tumors, there is a paucity of data on associated prognostic factors. We used the Surveillance, Epidemiology, and End Results (SEER) database to evaluate prognostic factors for pineoblastomas with the aim of improving tumor management.

METHODS

Data from all pediatric patients (age ≤17 years) diagnosed with pineoblastoma between 1990 and 2013 were extracted from the SEER-18 registry database. Survival was described with Kaplan-Meier curves. The Cox proportional hazards model was used for both univariate and multivariate analyses. A nomogram was established for predicting 1-, 3-, and 5-year overall survival (OS) in patients with pineoblastoma.

RESULTS

Age >5 years (P = 0.004) and radiotherapy treatment (P = 0.000) were associated with better rates of survival. Gross total resection (P = 0.054) also was correlated with better prognosis, whereas tumor size >30 mm in maximum diameter (P = 0.025) was associated with poorer outcome. A nomogram was established based on the results of the Cox model and was validated by a concordance index (C-index) of 0.767 (95% confidence interval, 0.698-0.836) and calibration plots.

CONCLUSIONS

Our results show that the impact of tumor extension is not defined. OS is better in older children treated by radiotherapy, and gross total resection also appears to result in increased survival. A nomogram was built to predict 1-, 3-, and 5-year OS for these patients.

The incidence of brainstem primitive neuroectodermal tumors of childhood based on SEER data

PURPOSE

Incidence of BS primitive neuroectodermal tumors (BS-PNET) in children is not reported to date. Our main objectives were to estimate the incidence and report the outcome of BS-PNET in children.

METHODS

Data were collected using the Surveillance Epidemiology and End Results cancer registry.

RESULTS

From 1973 to 2013, we identified 83 pediatric patients (aged 0-21 years). Patients were divided into two age groups (0-3 years and 4-21 years). Median overall survival was 53 months. Patients in the older age group had a significant survival advantage (P < 0.001), as did those who received three modalities of therapy (surgery, chemotherapy, and radiation therapy) (P < 0.001) and patients with gross or subtotal tumor resection (P < 0.001).

CONCLUSIONS

This study presents the first estimate of incidence and the largest cohort of pediatric BS-PNETs to date. A high index of suspicion of BS-PNET in similar cases is crucial for diagnosis, treatment, and outcome.

Evaluation of age-dependent treatment strategies for children and young adults with pineoblastoma: analysis of pooled European Society for Paediatric Oncology (SIOP-E) and US Head Start data

Background

Pineoblastoma is a rare pineal region brain tumor. Treatment strategies have reflected those for other malignant embryonal brain tumors.

Patients and Methods

Original prospective treatment and outcome data from international trial groups were pooled. Cox regression models were developed considering treatment elements as time-dependent covariates.

Results

Data on 135 patients with pineoblastoma aged 0.01-20.7 (median 4.9) years were analyzed. Median observation time was 7.3 years. Favorable prognostic factors were age ≥4 years (hazard ratio [HR] for progression-free survival [PFS] 0.270, P < .001) and administration of radiotherapy (HR for PFS 0.282, P < .001). Metastatic disease (HR for PFS 2.015, P = .006), but not postoperative residual tumor, was associated with unfavorable prognosis. In 57 patients <4 years old, 5-year PFS/overall survival (OS) were 11 ± 4%/12 ± 4%. Two patients survived after chemotherapy only, while 3 of 16 treated with craniospinal irradiation (CSI) with boost, and 3 of 5 treated with high-dose chemotherapy (HDCT) and local radiotherapy survived. In 78 patients aged ≥4 years, PFS/OS were 72 ± 7%/73 ± 7% for patients without metastases, and 50 ± 10%/55 ± 10% with metastases. Seventy-three patients received radiotherapy (48 conventionally fractionated CSI, median dose 35.0 [18.0-45.0] Gy, 19 hyperfractionated CSI, 6 local radiotherapy), with (n = 68) or without (n = 6) chemotherapy. The treatment sequence had no impact; application of HDCT had weak impact on survival in older patients.

Conclusion

Survival is poor in young children treated without radiotherapy. In these patients, combination of HDCT and local radiotherapy may warrant further evaluation in the absence of more specific or targeted treatments. CSI combined with chemotherapy is effective for older non-metastatic patients.

Management and outcome of children and adolescents with non-medulloblastoma CNS embryonal tumors in Spain: room for improvement in standards of care

Non-medulloblastoma CNS embryonal tumors (former PNET/Pineoblastomas) are aggressive malignancies with poor outcome that have been historically treated with medulloblastoma protocols. The purpose of this study is to present a tumor-specific, real-world data cohort of patients with CNS-PNET/PB to analyze quality indicators that can be implemented to improve the outcome of these patients. Patients 0-21 years with CNS-PNET treated in eight large institutions were included. Baseline characteristics, treatment and outcome [progression-free and overall survival (PFS and OS respectively)] were analyzed. From 2005 to 2014, 43 patients fulfilled entry criteria. Median age at diagnosis was 3.6 years (range 0.0-14.7). Histology was pineoblastoma (9%), ependymoblastoma (5%), ETANTR (7%) and PNET (77%). Median duration of the main symptom was 2 weeks (range 0-12). At diagnosis, 28% presented with metastatic disease. Seventeen different protocols were used on frontline treatment; 44% had gross total resection, 42% craniospinal radiotherapy, 86% chemotherapy, and 33% autologous hematopoietic stem cell transplantation (aHSCT). Median follow-up for survivors was 3.5 years (range 1.7-9.3). 3-year PFS was 31.9% (95% CI 17-47%) and OS 35.1% (95% CI 20-50%). Age, extent of resection and radiotherapy were prognostic of PFS and OS in univariate analysis (p < 0.05). Our series shows a dismal outcome for CNS-PNET, especially when compared to patients included in clinical trials. Establishing a common national strategy, implementing referral circuits and collaboration networks, and incorporating new molecular knowledge into routine clinical practice are accessible measures that can improve the outcome of these patients.

The case for DNA methylation based molecular profiling to improve diagnostic accuracy for central nervous system embryonal tumors (not otherwise specified) in adults

Central nervous system primitive neuro-ectodermal tumors (CNS-PNETs), have recently been re-classified in the most recent 2016 WHO Classification into a standby catch all category, "CNS Embryonal Tumor, not otherwise specified" (CNS embryonal tumor, NOS) based on epigenetic, biologic and histopathologic criteria. CNS embryonal tumors (NOS) are a rare, histologically and molecularly heterogeneous group of tumors that predominantly affect children, and occasionally adults. Diagnosis of this entity continues to be challenging and the ramifications of misdiagnosis of this aggressive class of brain tumors are significant. We report the case of a 45-year-old woman who was diagnosed with a central nervous system embryonal tumor (NOS) based on immunohistochemical analysis of the patient's tumor at diagnosis. However, later genome-wide methylation profiling of the diagnostic tumor undertaken to guide treatment, revealed characteristics most consistent with IDH-mutant astrocytoma. DNA sequencing and immunohistochemistry confirmed the presence of IDH1 and ATRX mutations resulting in a revised diagnosis of high-grade small cell astrocytoma, and the implementation of a less aggressive treatment regime tailored more appropriately to the patient's tumor type. This case highlights the inadequacy of histology alone for the diagnosis of brain tumours and the utility of methylation profiling and integrated genomic analysis for the diagnostic verification of adults with suspected CNS embryonal tumor (NOS), and is consistent with the increasing realization in the field that a combined diagnostic approach based on clinical, histopathological and molecular data is required to more accurately distinguish brain tumor subtypes and inform more effective therapy.

Genomic Analysis in the Practice of Surgical Neuropathology: The Emory Experience

The evaluation of central nervous system tumors increasingly relies on molecular genetic methods to aid in classification, offer prognostic information, and predict response to therapy. Available assays make it possible to assess genetic losses, amplifications, translocations, mutations, or the expression levels of specific gene transcripts or proteins. Current molecular diagnostics frequently use a panel-based approach and whole genome analysis, and generally rely either on DNA sequencing or on hybridization-based methodologies, such as those used in cytogenomic microarrays. In some cases, immunohistochemistry can be used as a surrogate for genetic analysis when the mutation of interest consistently results in overexpression or underexpression of a known protein product. In surgical neuropathology practice, the diagnostic workup of diffuse gliomas, medulloblastomas, low-grade circumscribed gliomas, as well as other diseases, now routinely incorporates the results of genomic studies. Here we summarize our institution's current approach to diagnostic surgical neuropathology, using these contemporary molecular diagnostic applications.

Pediatric Ependymoma

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

Treatment Outcome and Prognostic Molecular Markers of Supratentorial Primitive Neuroectodermal Tumors

Background

To identify prognostic factors and define the optimal management of patients with supratentorial primitive neuroectodermal tumors (sPNETs), we investigated treatment outcomes and explored the prognostic value of specific molecular markers.

Methods

A total of 47 consecutive patients with pathologically confirmed sPNETs between May 1985 and June 2012 were included. Immunohistochemical analysis of LIN28, OLIG2, and Rad51 expression was performed and correlated with clinical outcome.

Results

With a median follow-up of 70 months, 5-year overall survival (OS) and progression-free survival (PFS) was 55.5% and 40%, respectively, for all patients. Age, surgical extent, and radiotherapy were significant prognostic factors for OS and PFS. Patients who received initially planned multimodal treatment without interruption (i.e., radiotherapy and surgery (≥subtotal resection), with or without chemotherapy) showed significantly higher 5-year OS (71.2%) and PFS (63.1%). In 29 patients with available tumor specimens, tumors with high expression of either LIN28 or OLIG2 or elevated level of Rad51 were significantly associated with poorer prognosis.

Conclusions

We found that multimodal treatment improved outcomes for sPNET patients, especially when radiotherapy and ≥subtotal resection were part of the treatment regimen. Furthermore, we confirmed the prognostic significance of LIN28 and OLIG2 and revealed the potential role of Rad51 in sPNETs.

Pediatric Primitive Neuroectodermal Tumors of the Central Nervous System Differentially Express Granzyme Inhibitors

BACKGROUND

Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) are malignant primary brain tumors that occur in young infants. Using current standard therapy, up to 80% of the children still dies from recurrent disease. Cellular immunotherapy might be key to improve overall survival. To achieve efficient killing of tumor cells, however, immunotherapy has to overcome cancer-associated strategies to evade the cytotoxic immune response. Whether CNS-PNETs can evade the immune response remains unknown.

METHODS

We examined by immunohistochemistry the immune response and immune evasion strategies in pediatric CNS-PNETs.

RESULTS

Here, we show that CD4+, CD8+, γδ-T-cells, and Tregs can infiltrate pediatric CNS-PNETs, although the activation status of cytotoxic cells is variable. Pediatric CNS-PNETs evade immune recognition by downregulating cell surface MHC-I and CD1d expression. Intriguingly, expression of SERPINB9, SERPINB1, and SERPINB4 is acquired during tumorigenesis in 29%, 29%, and 57% of the tumors, respectively.

CONCLUSION

We show for the first time that brain tumors express direct granzyme inhibitors (serpins) as a potential mechanism to overcome cellular cytotoxicity, which may have consequences for cellular immunotherapy.

Paediatric brain tumours: A review of radiotherapy, state of the art and challenges for the future regarding protontherapy and carbontherapy

BACKGROUND AND PURPOSE

Brain tumours are the most frequent solid tumours in children and the most frequent radiotherapy indications in paediatrics, with frequent late effects: cognitive, osseous, visual, auditory and hormonal. A better protection of healthy tissues by improved beam ballistics, with particle therapy, is expected to decrease significantly late effects without decreasing local control and survival. This article reviews the scientific literature to advocate indications of protontherapy and carbon ion therapy for childhood central nervous system cancer, and estimate the expected therapeutic benefits.

MATERIALS AND METHODS

A systematic review was performed on paediatric brain tumour treatments using Medline (from 1966 to March of 2014). To be included, clinical trials had to meet the following criteria: age of patients 18 years or younger, treated with radiation, and report of survival. Studies were also selected according to the evidence level. A secondary search of cited references found other studies about cognitive functions, quality of life, the comparison of photon and proton dosimetry showing potential dose escalation and/or sparing of organs at risk with protontherapy; and studies on dosimetric and technical issues related to protontherapy.

RESULTS

A total of 7051 primary references published were retrieved, among which 40 clinical studies and 60 papers about quality of life, dose distribution and dosimetry were analysed, as well as the ongoing clinical trials. These papers have been summarized and reported in a specific document made available to the participants of a final 1-day workshop. Tumours of the meningeal envelop and bony cranial structures were excluded from the analysis. Protontherapy allows outstanding ballistics to target the tumour area, while substantially decreasing radiation dose to the normal tissues. There are many indications of protontherapy for paediatric brain tumours in curative intent, either for localized treatment of ependymomas, germ-cell tumours, craniopharyngiomas, low-grade gliomas; or panventricular irradiation of pure non-secreting germinoma; or craniospinal irradiation of medulloblastomas and metastatic pure germinomas. Carbon ion therapy is just emerging and may be studied for highly aggressive and radioresistant tumours, as an initial treatment for diffuse brainstem gliomas, and for relapse of high-grade gliomas.

CONCLUSION

Both protontherapy and carbon ion therapy are promising for paediatric brain tumours. The benefit of decreasing late effects without altering survival has been described for most paediatric brain tumours with protontherapy and is currently assessed in ongoing clinical trials with up-to-date proton devices. Unfortunately, in 2015, only a minority of paediatric patients in France can receive protontherapy due to the lack of equipment.

Treatment outcome and patterns of failure in patients of pinealoblastoma: review of literature and clinical experience from a regional cancer centre in north India

PURPOSE

Pinealoblastoma is a highly malignant embryonal tumour of the pineal region affecting children and young adults. We herein intend to report the clinical features and treatment outcome of patients of pinealoblastoma treated at our institute.

METHODS

Clinical data was collected by retrospective chart review from 2003-2012. Histopathology slides were reviewed, and relevant immunohistochemistry stains were done. Overall survival (OS) and recurrence-free survival (RFS) were analysed by Kaplan-Meier product-limit method. Univariate and multivariate analyses of prognostic factors were done by log rank test and Cox proportional hazard regression model, respectively.

RESULTS

Seventeen patients met the study criterion (male:female = 11:6). Median age at presentation was 14 years (range 4-47 years). Surgical resection was gross total in 6 (35.29%), near-total in 2 (11.76%), sub-total in 2 (11.76%), and limited to biopsy in 7 (41.18 %) patients. At presentation, 4 patients had leptomeningeal dissemination. Radiation therapy was delivered in all patients-craniospinal irradiation in 15 (88.24%), whole brain irradiation in 1 (5.88%), and whole ventricular irradiation followed by boost in 1 (5.88%) patient. Systemic chemotherapy (median 6 cycles) was given in 14 (82.35%) patients. The most common regimen was a combination of carboplatin and etoposide, used in 10 (58.82%) patients. After a median follow-up of 30.3 months (mean 32.01 months), death and disease recurrences were noted in 3 (17.65%) and 7 (41.18%) patients. Amongst the patients with recurrent disease, 4 had spinal drop metastases and 3 had local recurrence along with spinal drop metastases. Median OS was not reached, and estimated median RFS was noted to be 5.49 years. The actuarial rates of OS and RFS at 2 years were 85.6 and 73.1%, respectively. On univariate analysis, age more than 8 years (P = 0.0071) and M0 stage (P = 0.0483) were significant predictors of improved RFS. Age retained significance on multivariate analysis of RFS (P = 0.02932).

CONCLUSION

Maximal safe resection followed by craniospinal irradiation and systemic chemotherapy with 6 cycles of carboplatin-etoposide regimen is a reasonable treatment strategy in patients of pinealoblastoma more than 8 years of age in a developing nation. However, the same strategy is less effective in younger children and innovative study designs of intensification of post-operative treatment must be explored in this age group.

Embryonal brain tumors

Embryonal brain tumors are a heterogeneous group of neoplasms that primarily occur in infants and young children. They are highly cellular tumors with brisk mitotic activity, and they share a propensity for dissemination throughout the neuroaxis. Emerging molecular data enable improved diagnostic and prognostic discrimination for these tumors. Because of their aggressive potential, they are treated similarly with multimodality therapy including maximal safe resection, chemotherapy, and age- and risk-adapted radiotherapy. Craniospinal irradiation is commonly used in the treatment of these patients, especially in those older than 3 years. Because proton therapy allows for increased sparing of the anterior structures in craniospinal irradiation, there is a particular interest in using proton therapy to treat these young patients. For very young patients treated with focal fields only, proton therapy also decreases unnecessary radiation exposure to uninvolved intracranial structures. It is hoped that the use of proton therapy for these vulnerable patients will translate into decreased long-term neurocognitive, endocrine, vascular, and developmental effects, in addition to a decreased risk of second malignancies. This review describes the role of radiation in general and proton therapy in particular for the treatment of medulloblastoma, central nervous system primitive neuroectodermal tumors, atypical teratoid/rhabdoid tumors, and the recently described embryonal tumor with multilayered rosettes.

Treatment outcome and patterns of failure in patients of non-pineal supratentorial primitive neuroectodermal tumor: review of literature and clinical experience form a regional cancer center in north India

BACKGROUND

Supra-tentorial primitive neuroectodermal tumors (SPNET) are high-grade, hemispheric tumors, which account for around 2-3 % of pediatric brain tumors. We herein intend to report the clinical features and treatment outcome of patients with nonpineal SPNET treated at our institute.

METHODS

Clinical data were collected by retrospective chart review from 2006 to 2012. Histopathology slides were reviewed, and relevant immunohistochemistry stains were done. Overall survival (OS), recurrence-free survival (RFS) and event-free survival (EFS) were analyzed by the Kaplan-Meier product-limit method.

RESULTS

Fifteen patients met the study criterion (male: female = 2:1). Median age at presentation was 11 years (range 3-49 years). Surgical resection was gross total in 6 (40%) and subtotal in 8 (53.33%) patients. At presentation, two patients had leptomeningeal dissemination. Radiation therapy was delivered in 11 (73.33%) patients: craniospinal irradiation in 8 (36 Gy/20 fractions/4 weeks to the craniospinal axis followed by a local boost of 20 Gy/10 fractions/2 weeks) and focal RT in 3 patients. Systemic chemotherapy (median 6 cycles; range 1-16 cycles), given in 13 (86.67%) patients, included the VAC regimen (vincristine, adriamycin, cyclophosphamide) alternating with IE (ifosfamide,etoposide). After a median follow-up of 22.6 months (mean, 24.47 months), complete response and progressive disease were noted in 8 (53.33%) and 7 (46.67%) patients, respectively. Median OS was not reached, and estimated median EFS was noted to be 4.12 years (actuarial rate of EFS at 2 years, 55.2%).

CONCLUSION

Maximal safe resection followed by craniospinal irradiation and systemic chemotherapy with 6-12 cycles of an alternating regimen of VAC and IE is a reasonable treatment strategy in patients with nonpineal SPNET.

Diffusion characteristics of pediatric pineal tumors

BACKGROUND

Diffusion weighted imaging (DWI) has been shown to be helpful in characterizing tumor cellularity, and predicting histology. Several works have evaluated this technique for pineal tumors; however studies to date have not focused on pediatric pineal tumors.

OBJECTIVE

We evaluated the diffusion characteristics of pediatric pineal tumors to confirm if patterns seen in studies using mixed pediatric and adult populations remain valid.

MATERIALS AND METHODS

This retrospective study was performed after Institutional Review Board approval. We retrospectively evaluated all patients 18 years of age and younger with pineal tumors from a single institution where preoperative diffusion weighted imaging as well as histologic characterization was available.

RESULTS

Twenty patients (13 male, 7 female) with pineal tumors were identified: seven with pineoblastoma, four with Primitive Neuroectodermal Tumor (PNET), two with other pineal tumors, and seven with germ cell tumors including two germinomas, three teratomas, and one mixed germinoma-teratoma. The mean apparent diffusion coefficient (ADC) values in pineoblastoma (544 ± 65 × 10⁻⁶ mm²/s) and pineoblastoma/PNET (595 ± 144 × 10⁻⁶ mm²/s) was lower than that of the germ cell tumors (1284 ± 334 × 10⁻⁶ mm²/s; p < 0.0001 vs pineoblastoma). One highly cellular germinoma had an ADC value of 694 × 10⁻⁶ mm²/s.

CONCLUSION

ADC values can aid in differentiation of pineoblastoma/PNET from germ cell tumors in a population of children with pineal masses.

Intracranial cystic lesions: a review

Cysts and cystic-appearing intracranial lesions are common findings with routine cerebral imaging examination. These lesions often represent a challenge in diagnosis. Intracranial cystic lesions have wide pathologic and imaging spectra, of which some require an aggressive and tailored treatment, whereas many others remain asymptomatic and do not require follow-up or intervention. Intracranial cysts can be divided in non-neoplastic lesions that are often of developmental origin but comprise as well infectious cysts and neoplastic lesions that include benign cysts associated with low-grade tumors and cysts as a component of higher grade neoplasms. Reviewed are the pathology, origin, radiologic appearance, differential diagnosis, and therapeutic aspects of intracranial cystic lesions.

Primitive neuroectodermal tumors of the brainstem in children treated according to the HIT trials: clinical findings of a rare disease

OBJECT

Primitive neuroectodermal tumors of the central nervous system (CNS-PNET) arising in the brainstem are extremely rare, and knowledge about them is limited. The few existing case series report fatal outcomes. The purpose of this study was to analyze clinical characteristics of and outcome for brainstem CNS-PNET patients treated according to the consecutive, population-based HIT studies covering a 19-year time period.

METHODS

Between September 1992 and November 2011, 6 eligible children with histologically proven brainstem CNS-PNET not otherwise specified and 2 children with brainstem ependymoblastomas (3, partial resection; 3, subtotal resection; 2, biopsy), median age 3.3 years (range 1.2-10.6 years), were treated according to consecutive multimodal HIT protocols for CNS-PNET/medulloblastoma. Postoperative treatment was according to maintenance chemotherapy protocols (3, craniospinal irradiation [CSI] followed by maintenance chemotherapy), sandwich chemotherapy protocols (2, neoadjuvant chemotherapy, CSI, maintenance chemotherapy), or a therapy protocol for children younger than 4 years (3, postoperative chemotherapy followed by CSI).

RESULTS

The median duration of prediagnostic symptoms, predominantly cranial nerve deficits (n = 7), pyramidal tract signs (n = 5), or ataxia (n = 5), was 5 weeks (range 1-13 weeks). The tumors were all located in the pons. Most involved more than half of the pontine axial diameter and were sharply marginated. All patients had postoperative residual disease, including metastasis in 1 case. With 1 exception all tumors progressed early during treatment within 3.9 months (range 2.5-10.4 months), leading to a 1-year event-free survival rate (± standard error) of 13% ± 12%. After progression, patients succumbed early to their disease resulting in a 1-year overall survival rate of 25% ± 15%. The only surviving patient had a partially resected CNS-PNET, received a sandwich chemotherapy protocol, and is without disease progression 14 months after diagnosis.

CONCLUSIONS

CNS-PNET is a rare but important differential diagnosis in childhood brainstem tumors. So far, efficient therapies are lacking. The sampling of tumor material for improved biological understanding and identification of new therapeutic targets is important.

Clinical outcomes and patterns of failure in pineoblastoma: a 30-year, single-institution retrospective review

OBJECTIVE

To update outcomes and assess prognostic factors in the modern, multimodality treatment of patients with pineoblastoma.

METHODS

The medical records of patients with pineoblastoma evaluated at the M.D. Anderson Cancer Center between 1982 and 2012 were reviewed retrospectively.

RESULTS

Thirty-one patients with medical records suitable for review were identified. The majority of patients were female (67.7%) with a median age at diagnosis of 18.2 years (range, 0.3-52.8 years). Twenty-one patients underwent surgical resection, recorded as gross total (n = 9) or subtotal (n = 12) resections. Thirty patients received radiation with photon-based therapy (n = 16), proton-based therapy (n = 13), or radiosurgery (n = 1) to a median craniospinal irradiation dose of 36 Gy (range, 23.4-40 Gy) and a median focal dose of 54 Gy (range, 40-58.4 Gy). Twenty-eight patients received chemotherapy before (n = 10), during (n = 10), and after (n = 22) radiation. Median overall survival was 8.7 years for the entire cohort, with 2-, 5-, and 10- year actuarial rates of 89.5%, 69.4%, and 48.6%, respectively. Median disease-free survival was 10 years with 2-, 5-, and 10- year actuarial rates of 84.3%, 62.6%, and 55.7%, respectively. Univariate analysis failed to correlate age, sex, or extent of surgical resection with disease-free or overall survival.

CONCLUSIONS

Modern, multimodality treatment of pineoblastoma yields a high rate of overall survival, with acceptable short- and long-term toxicity. A greater M-stage at presentation and development of disease recurrence correlate with worse overall survival. Patients who received focal radiation initially experienced a greater rate of disease recurrence compared with those treated to the craniospinal axis.

Advances in managing medulloblastoma and intracranial primitive neuro-ectodermal tumors

Medulloblastoma and central nervous system (CNS)-primitive neuro-ectodermal tumors (PNETs) are a diverse group of entities which encompasses different pathological and clinical pictures. Initially divided based on histology and location, molecular insight is leading to new definitions and a change in the borders delineating these diseases, such that they become more divergent. Current treatment approaches consist of surgical resection, radiotherapy and intensive chemotherapy, dependent on age. Stratification is one risk factor shown to be prognostic and is divided into high- and average-risks. Outcomes with modern treatment regimens are good, particularly in average-risk medulloblastoma patients, but the cost of cure is high, with high rates of neurocognitive, endocrine and social dysfunction. The changing biological landscape, however, may allow for clearer prediction of tumor behavior, to better identify "good" and "bad" players within these groups. Discovery of subgroups with changes in dependent molecular pathways will also lead to the development of new specific targeted therapies. Presenting exciting opportunities, these advances may transform the treatment for some patients, revolutionizing therapy in the future. Several challenges, however, are yet to be faced and caution is needed not to abandon previously defined prognostic factors on the strength of thus far retrospective evidence. We are witnessing a new era of trials with biological stratification involving multiple subgroups and treatment arms, based on specific tumor-related targets. This review discusses the changing face of medulloblastoma and CNS-PNETs and how we move molecular advances into clinical trials that benefit patients.

Evolving of therapeutic strategies for CNS-PNET

BACKGROUND

A protocol for the intensive treatment of non-cerebellar PNET (CNS-PNET) combining chemotherapy and radiotherapy was launched in 2000. Efforts were subsequently made to improve the prognosis and to de-escalate the treatment for selected patient groups.

PROCEDURE

Twenty-eight consecutive patients were enrolled for a high-dose drug schedule (methotrexate, etoposide, cyclophosphamide, and carboplatin ± vincristine), followed by hyperfractionated accelerated CSI (HART-CSI) at total doses of 31-39 Gy, depending on the patient's age, with two high-dose thiotepa courses following CSI. After the first 15 patients had been treated, craniospinal irradiation (CSI) was replaced with focal radiotherapy (RT) for selected cases (non-metastatic and not progressing during induction chemotherapy). Eight of the 28 children received the same chemotherapy but conventionally fractionated focal RT at 54 Gy.

RESULTS

The 5-year progression-free survival (PFS), event-free survival (EFS), and overall survival (OS) rates were 62%, 53%, and 52%, respectively, for the whole series, and 70%, 70%, and 87% for the eight focally irradiated children. Residual disease and metastases were not prognostically significant. In children with residual disease, response to RT was significant (5-year PFS 59% vs. 20%, P = 0.01), while the total dose of CSI was not. There were three treatment-related toxic events. Relapses were local in seven cases (including two of the eight focally irradiated patients), and both local and disseminated in 2.

CONCLUSIONS

This intensive schedule enabled treatment stratification for the purposes of radiation, thereby sparing some children full-dose CSI. Local control is the main goal of treatment for CNS-PNET.

Historical trends in the use of radiation therapy for pediatric cancers: 1973-2008

PURPOSE

This study was undertaken to assess historical trends in the use of radiation therapy (RT) for pediatric cancers over the past 4 decades.

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results database of the 9 original tumor registries (SEER-9) was queried to identify patients aged 0 to 19 years with acute lymphoblastic leukemia, acute myeloid leukemia, bone and joint cancer, cancer of the brain and nervous system, Hodgkin lymphoma, neuroblastoma, non-Hodgkin lymphoma, soft tissue cancer, Wilms tumor, or retinoblastoma from 1973 to 2008. Patients were grouped into 4-year time epochs. The number and percentage of patients who received RT as part of their initial treatment were calculated per epoch by each diagnosis group from 1973 to 2008.

RESULTS

RT use for acute lymphoblastic leukemia, non-Hodgkin lymphoma, and retinoblastoma declined sharply from 57%, 57%, and 30% in 1973 to 1976 to 11%, 15%, and 2%, respectively, in 2005 to 2008. Similarly, smaller declines in RT use were also seen in brain cancer (70%-39%), bone cancer (41%-21%), Wilms tumor (75%-53%), and neuroblastoma (60%-25%). RT use curves for Wilms tumor and neuroblastoma were nonlinear with nadirs in 1993 to 1996 at 39% and 19%, respectively. There were minimal changes in RT use for Hodgkin lymphoma, soft tissue cancer, or acute myeloid leukemia, roughly stable at 72%, 40%, and 11%, respectively. Almost all patients treated with RT were given external beam RT exclusively. However, from 1985 to 2008, treatments involving brachytherapy, radioisotopes, or combination therapy increased in frequency, comprising 1.8%, 4.6%, and 11.9% of RT treatments in brain cancer, soft tissue cancer, and retinoblastoma, respectively.

CONCLUSIONS

The use of RT is declining over time in 7 of 10 pediatric cancer categories. A limitation of this study is a potential under-ascertainment of RT use in the SEER-9 database including the delayed use of RT.

Treatment of young children with CNS-primitive neuroectodermal tumors/pineoblastomas in the prospective multicenter trial HIT 2000 using different chemotherapy regimens and radiotherapy

BACKGROUND

Especially in young children, primitive neuroectodermal tumors of the central nervous system (CNS-PNET) and pineoblastomas are associated with an unfavorable outcome, and only a few prospective trials have been conducted thus far.

METHODS

From January 2001 through January 2005, 17 eligible children aged <4 years with CNS-PNET not otherwise specified (n = 8), ependymoblastoma (n = 1), or pineoblastoma (n = 8) confirmed by central review were prospectively treated in the trial HIT 2000. In nonmetastatic disease (n = 11), up to 5 postoperative cycles of HIT-SKK systemic multiagent chemotherapy (8 months duration), followed by craniospinal radiotherapy (CSI), were given. In metastatic disease (M1-M3, n = 6), treatment consisted of a shorter induction chemotherapy (2-3 months) with carboplatin and etoposide, followed by tandem high-dose chemotherapy (HDCT) in case of good response to induction. During induction and HDCT, patients received intraventricular methotrexate. CSI was applied to all patients with poor response to induction or residual disease after HDCT and was optional for patients with residual disease before HDCT.

RESULTS

Five-year event-free survival and overall survival rates ± standard error for all eligible patients were 24% ± 10% and 40% ± 12%, respectively (median follow-up of survivors: 8.3 years). Only one patient with nonmetastatic disease remained free of relapse/progressive disease during induction. Three of 6 patients with metastatic disease responded to induction and received tandem-HDCT, followed by preventive CSI, and remain in continuous complete remission.

CONCLUSIONS

Short intensive induction chemotherapy followed by tandem-HDCT in young children with CNS-PNET/pineoblastomas seems to be superior to the prolonged and less intensive induction regimen.

Primary pineal tumors: outcome and prognostic factors--a study from the Rare Cancer Network (RCN)

PURPOSE

To better define outcome and prognostic factors in primary pineal tumors.

MATERIALS AND METHODS

Thirty-five consecutive patients from seven academic centers of the Rare Cancer Network diagnosed between 1988 and 2006 were included. Median age was 36 years. Surgical resection consisted of biopsy in 12 cases and resection in 21 (2 cases with unknown resection). All patients underwent radiotherapy and 12 patients received also chemotherapy.

RESULTS

Histological subtypes were pineoblastoma (PNB) in 21 patients, pineocytoma (PC) in 8 patients and pineocytoma with intermediate differentiation in 6 patients. Six patients with PNB had evidence of spinal seeding. Fifteen patients relapsed (14 PNB and 1 PC) with PNB cases at higher risk (p = 0.031). Median survival time was not reached. Median disease-free survival was 82 months (CI 50 % 28-275). In univariate analysis, age younger than 36 years was an unfavorable prognostic factor (p = 0.003). Patients with metastases at diagnosis had poorer survival (p = 0.048). Late side effects related to radiotherapy were dementia, leukoencephalopathy or memory loss in seven cases, occipital ischemia in one, and grade 3 seizures in two cases. Side effects related to chemotherapy were grade 3-4 leucopenia in five cases, grade 4 thrombocytopenia in three cases, grade 2 anemia in two cases, grade 4 pancytopenia in one case, grade 4 vomiting in one case and renal failure in one case.

CONCLUSIONS

Age and dissemination at diagnosis influenced survival in our series. The prevalence of chronic toxicity suggests that new adjuvant strategies are advisable.

Markers of survival and metastatic potential in childhood CNS primitive neuro-ectodermal brain tumours: an integrative genomic analysis

BACKGROUND

Childhood CNS primitive neuro-ectodermal brain tumours (PNETs) are very aggressive brain tumours for which the molecular features and best treatment approaches are unknown. We assessed a large cohort of these rare tumours to identify molecular markers to enhance clinical management of this disease.

METHODS

We obtained 142 primary hemispheric CNS PNET samples from 20 institutions in nine countries and examined transcriptional profiles for a subset of 51 samples and copy number profiles for a subset of 77 samples. We used clustering, gene, and pathway enrichment analyses to identify tumour subgroups and group-specific molecular markers, and applied immunohistochemical and gene-expression analyses to validate and assess the clinical significance of the subgroup markers.

FINDINGS

We identified three molecular subgroups of CNS PNETs that were distinguished by primitive neural (group 1), oligoneural (group 2), and mesenchymal lineage (group 3) gene-expression signatures with differential expression of cell-lineage markers LIN28 and OLIG2. Patients with group 1 tumours were most often female (male:female ratio 0·61 for group 1 vs 1·25 for group 2 and 1·63 for group 3; p=0·043 [group 1 vs groups 2 and 3]), youngest (median age at diagnosis 2·9 years [95% CI 2·4-5·2] for group 1 vs 7·9 years [6·0-9·7] for group 2 and 5·9 years [4·9-7·8] for group 3; p=0·005), and had poorest survival (median survival 0·8 years [95% CI 0·5-1·2] in group 1, 1·8 years [1·4-2·3] in group 2 and 4·3 years [0·8-7·8] in group 3; p=0·019). Patients with group 3 tumours had the highest incidence of metastases at diagnosis (no distant metastasis:metastasis ratio 0·90 for group 3 vs 2·80 for group 1 and 5·67 for group 2; p=0·037).

INTERPRETATION

LIN28 and OLIG2 are promising diagnostic and prognostic molecular markers for CNS PNET that warrant further assessment in prospective clinical trials.

FUNDING

Canadian Institute of Health Research, Brainchild/SickKids Foundation, and the Samantha Dickson Brain Tumour Trust.

DNA copy number alterations in central primitive neuroectodermal tumors and tumors of the pineal region: an international individual patient data meta-analysis

Little is known about frequency, association with clinical characteristics, and prognostic impact of DNA copy number alterations (CNA) on survival in central primitive neuroectodermal tumors (CNS-PNET) and tumors of the pineal region. Searches of MEDLINE, Pubmed, and EMBASE--after the original description of comparative genomic hybridization in 1992 and July 2010--identified 15 case series of patients with CNS-PNET and tumors of the pineal region whose tumors were investigated for genome-wide CNA. One additional case study was identified from contact with experts. Individual patient data were extracted from publications or obtained from investigators, and CNAs were converted to a digitized format suitable for data mining and subgroup identification. Summary profiles for genomic imbalances were generated from case-specific data. Overall survival (OS) was estimated using the Kaplan-Meier method, and by univariable and multivariable Cox regression models. In their overall CNA profiles, low grade tumors of the pineal region clearly diverged from CNS-PNET and pineoblastoma. At a median follow-up of 89 months, 7-year OS rates of CNS-PNET, pineoblastoma, and low grade tumors of the pineal region were 22.9 ± 6, 0 ± 0, and 87.5 ± 12 %, respectively. Multivariable analysis revealed that histology (CNS-PNET), age (≤2.5 years), and possibly recurrent CNAs were associated with unfavorable OS. DNA copy number profiling suggests a close relationship between CNS-PNET and pineoblastoma. Low grade tumors of the pineal region differed from CNS-PNET and pineoblastoma. Due to their high biological and clinical variability, a coordinated prospective validation in future studies is necessary to establish robust risk factors.

Medulloblastoma and primitive neuroectodermal tumors

Medulloblastomas and sPNETs remain highly problematic tumors to treat. Prognosis has improved over the past two decades, but many children who survive treatment have significant long-term sequelae. The improvements in outcome have been due to advances in surgical techniques, the wider use of chemotherapy, and the more judicious use of radiotherapy. For further improvements,the recent impressive discoveries concerning molecular mechanisms of embryonal tumor origin, development,and growth will need to be translated into molecularly based, risk-adapted therapy.

Long-term survival in a pediatric patient with supratentorial primitive neuro-ectodermal tumor and extraneural metastasis at diagnosis

Extraneural metastases of central nervous system (CNS) tumors are rare occurrences most commonly observed in medulloblastomas. Survival outcomes are generally dismal. Supratentorial primitive neuroectodermal tumors (stPNET) are rare childhood tumors with few documented cases of extraneural metastases. We present a rare occurrence of a 23-month-old patient with long-term survival after diagnosis of stPNET with metastases to the lungs. This patient was treated with surgical resection, induction chemotherapy, tandem autologous hematopoietic cell rescues, and focal radiotherapy. We report long-term survival for a patient with a stPNET and extraneural metastases at diagnosis following an intensive approach to treatment.

Supratentorial PNET in a young child

Primitive Neuroectodermal tumours (PNET) are small-cell malignant embryonal tumors showing divergent differentiation of variable degree into neuronal, glial, or rarely mesenchymal tissues. PNET belongs to the Ewing family of tumors. Tumors that fall under the heading PNET include medulloblastoma (commonest), pineoblastoma, pendymoblastoma, retinoblastoma, neuroblastoma and esthesioneuroblastoma. Ependymoblastoma is a synonym for PNET.

Non-cerebellar primitive neuroectodermal tumors (PNET): summary of the Milan consensus and state of the art workshop on marrow ablative chemotherapy with hematopoietic cell rescue for malignant brain tumors of childhood and adolescents

CNS non-cerebellar primitive neuroectodermal tumors (PNET) represent <5% of all childhood brain tumors. Despite similar therapies, these patients have had significantly worse outcomes compared to patients with medulloblastoma. Although these tumors have historically been considered analogous to medulloblastoma, there is growing evidence that they are biologically distinct. Since these tumors are relatively rare, there are few large series in the literature. Here we present the international experience treating these patients with a variety of therapies, including marrow ablative chemotherapy followed by autologous hematopoietic cell rescue.

Successful radiation therapy for supratentorial primitive neuroectodermal tumor and epidermolysis bullosa simplex

Epidermolysis bullosa simplex (EBS) is a heritable skin disorder characterized by skin fragility and blistering. While its most severe variant, dystrophic epidermolysis bullosa (DEB) is associated with squamous cell carcinoma (SCC), the development of extracutaneous neoplasms in EBS is extremely rare. We report a novel case of supratentorial primitive neuroectodermal tumor (sPNET) in a 7-year male with EBS. Experience of radiation therapy and its challenges in children with EBS has rarely been reported.

Safety and toxicity of intrathecal liposomal cytarabine (Depocyte) in children and adolescents with recurrent or refractory brain tumors: a multi-institutional retrospective study

This retrospective study aimed to evaluate the safety and toxicity of intrathecal liposomal cytarabine (Depocyte) in children and adolescents with refractory or recurrent brain tumors. Nineteen heavily pretreated patients (males, n = 14; females, n = 5; median age at diagnosis 8.5 years; range, 1.4-22 years) were given intrathecal liposomal cytarabine on a compassionate use basis for recurrent refractory medulloblastoma (n = 12), mixed germ cell tumor (n = 2), central nervous system primitive neuroectodermal tumors of the pons (n = 1), anaplastic ependymoma (n = 1), anaplastic oligodendroglioma (n = 1), atypical teratoid rhabdoid tumor (n = 1), or rhabdoid papillary meningioma (n = 1). Eighteen patients received concomitant systemic radiochemotherapy. A total of 88 intrathecal injections of liposomal cytarabine (dose range, 20-50 mg) were administered with concomitant dexamethasone prophylaxis. The median number of doses per patient was four (range, 1-10). Duration of treatment ranged from (1/2) to 10 months. Eleven patients (57.9%) did not show any side effects, whereas eight patients (42.1%) developed side effects related to either chemical arachnoiditis (n = 4) or neurological progression (n = 2). Less typical treatment-related symptoms (e.g. lethargy, ataxia, and slurred speech) were observed in two patients. Treatment with intrathecal liposomal cytarabine was discontinued twice because of side effects. In conclusion, although intrathecal liposomal cytarabine was generally well tolerated, it should be used cautiously and only with dexamethasone prophylaxis in extensively pretreated patients with recurrent brain tumors. Proof of efficacy requires a prospective single-agent phase II study.

Frequent amplification of a chr19q13.41 microRNA polycistron in aggressive primitive neuroectodermal brain tumors

We discovered a high-level amplicon involving the chr19q13.41 microRNA (miRNA) cluster (C19MC) in 11/45 ( approximately 25%) primary CNS-PNET, which results in striking overexpression of miR-517c and 520g. Constitutive expression of miR-517c or 520g promotes in vitro and in vivo oncogenicity, modulates cell survival, and robustly enhances growth of untransformed human neural stem cells (hNSCs) in part by upregulating WNT pathway signaling and restricting differentiation of hNSCs. Remarkably, the C19MC amplicon, which is very rare in other brain tumors (1/263), identifies an aggressive subgroup of CNS-PNET with distinct gene-expression profiles, characteristic histology, and dismal survival. Our data implicate miR-517c and 520g as oncogenes and promising biological markers for CNS-PNET and provide important insights into oncogenic properties of the C19MC locus.

Current treatment approaches for infants with malignant central nervous system tumors

The management of brain tumors in very young children remains a challenge for neuro-oncologists in large part because of the greater vulnerability of the developing brain to treatment-related toxicity. Nearly three decades of infant brain tumor clinical trials have led to significant progress in the delineation of prognostic factors and improvements in outcome. Innovative strategies that employ high-dose chemotherapy, intrathecal chemotherapy, modified focal irradiation, or combinations of these have been used to delay or avoid the use of conventional craniospinal irradiation in order to minimize the risk for deleterious neurocognitive impairment in survivors. However, it is difficult to evaluate the impact of such approaches on intellectual and functional outcome, and results to date are limited. This review covers the most recent therapeutic advances for the most common histological subtypes of malignant infant brain tumors: medulloblastoma, supratentorial primitive neuroectodermal tumor, ependymoma, atypical teratoid rhabdoid tumor, choroid plexus carcinoma, and high-grade glioma. Survival and neurocognitive outcome are emphasized.

Stray radiation dose and second cancer risk for a pediatric patient receiving craniospinal irradiation with proton beams

Proton beam radiotherapy unavoidably exposes healthy tissue to stray radiation emanating from the treatment unit and secondary radiation produced within the patient. These exposures provide no known benefit and may increase a patient's risk of developing a radiogenic cancer. The aims of this study were to calculate doses to major organs and tissues and to estimate second cancer risk from stray radiation following craniospinal irradiation (CSI) with proton therapy. This was accomplished using detailed Monte Carlo simulations of a passive-scattering proton treatment unit and a voxelized phantom to represent the patient. Equivalent doses, effective dose and corresponding risk for developing a fatal second cancer were calculated for a 10-year-old boy who received proton therapy. The proton treatment comprised CSI at 30.6 Gy plus a boost of 23.4 Gy to the clinical target volume. The predicted effective dose from stray radiation was 418 mSv, of which 344 mSv was from neutrons originating outside the patient; the remaining 74 mSv was caused by neutrons originating within the patient. This effective dose corresponds to an attributable lifetime risk of a fatal second cancer of 3.4%. The equivalent doses that predominated the effective dose from stray radiation were in the lungs, stomach and colon. These results establish a baseline estimate of the stray radiation dose and corresponding risk for a pediatric patient undergoing proton CSI and support the suitability of passively-scattered proton beams for the treatment of central nervous system tumors in pediatric patients.

An investigation of WNT pathway activation and association with survival in central nervous system primitive neuroectodermal tumours (CNS PNET)

Central nervous system primitive neuroectodermal tumours (CNS PNET) are high-grade, predominantly paediatric, brain tumours. Previously they have been grouped with medulloblastomas owing to their histological similarities. The WNT/β-catenin pathway has been implicated in many tumour types, including medulloblastoma. On pathway activation β-catenin (CTNNB1) translocates to the nucleus, where it induces transcription of target genes. It is commonly upregulated in tumours by mutations in the key pathway components APC and CTNNB1. WNT/β-catenin pathway status was investigated by immunohistochemical analysis of CTNNB1 and the pathway target cyclin D1 (CCND1) in 49 CNS PNETs and 46 medulloblastomas. The mutational status of APC and CTNNB1 (β-catenin) was investigated in 33 CNS PNETs and 22 medulloblastomas. CTNNB1 nuclear localisation was seen in 36% of CNS PNETs and 27% of medulloblastomas. A significant correlation was found between CTNNB1 nuclear localisation and CCND1 levels. Mutations in CTNNB1 were identified in 4% of CNS PNETs and 20% of medulloblastomas. No mutations were identified in APC. A potential link between the level of nuclear staining and a better prognosis was identified in the CNS PNETs, suggesting that the extent of pathway activation is linked to outcome. The results suggest that the WNT/β-catenin pathway plays an important role in the pathogenesis of CNS PNETs. However, activation is not caused by mutations in CTNNB1 or APC in the majority of CNS PNET cases.

Long-term follow-up of renal function after high-dose methotrexate treatment in children

BACKGROUND

High-dose methotrexate (HD-MTX) is commonly used in treatment of pediatric leukemias and lymphomas. Transient deterioration in renal function is frequently noted during HD-MTX treatment, but possible long-term changes are less well known. In this study we aimed to study long-term renal prognosis after HD-MTX treatment, and to find possible underlying risk factors for reduced renal function.

PROCEDURE

Medical records of pediatric cancer patients treated with HD-MTX were reviewed retrospectively after follow-up of 1-10 years. Renal function before and after chemotherapy was investigated in a total of 28 patients. Assessment of glomerular and tubular function was prospectively evaluated in each case. Glomerular function was evaluated by either (51)Cr-EDTA or (99m)Tc-DTPA clearance methods, and by urinary albumin excretion. Tubular function was assessed by measuring blood electrolyte levels and urinary alpha(1)- or beta(2)-microglobulin.

RESULTS

A decrease in glomerular filtration rate (GFR) was statistically significant as follow-up time increased (P = 0.02). Age at the time of diagnosis and exposure to potentially nephrotoxic antibiotics during cancer treatment had no influence on GFR. However, albuminuria was observed more often in patients treated with amphotericin B or gentamycin (P = 0.04). No changes in tubular function were observed.

CONCLUSIONS

Our results show that HD-MTX treatment significantly decreases GFR and may cause albuminuria in pediatric cancer patients several years after treatment. Long-term renal follow-up of these patients is therefore important.

Treatment of early childhood medulloblastoma by postoperative chemotherapy and deferred radiotherapy

To investigate the utility of postoperative chemotherapy in delaying radiotherapy and to identify prognostic factors in early childhood medulloblastoma, we studied children younger than 3 years of age registered to the HIT-SKK'87 (Therapieprotokoll für Säuglinge und Kleinkinder mit Hirntumoren [Brain Tumor Radiotherapy for Infants and Toddlers with Medulloblastoma] 1987) trial who received systemic interval chemotherapy until craniospinal radiotherapy was applied at 3 years of age or at relapse, from 1987 to 1993. Children with postoperative residual tumor or metastatic disease received systemic induction chemotherapy prior to interval chemotherapy. Twenty-nine children were eligible for analyses (median age, 1.7 years; median follow-up, 12.6 years). In children without macroscopic metastases, rates (+/-SEM) for 10-year progression-free survival (PFS) and overall survival (OS) were 52.9% +/- 12.1% and 58.8% +/- 11.9% (complete resection), and 55.6% +/- 16.6% and 66.7% +/- 15.7% (incomplete resection), compared with 0% and 0% in children with macroscopic metastases. Survival was superior in nine children with desmoplastic or extensive nodular histology compared with 20 children with classic medulloblastoma (10-year PFS, 88.9% +/- 10.5% and 30.0% +/- 10.3%, p = 0.003; OS, 88.9% +/- 10.5% and 40.0% +/- 11.0%, p = 0.006). Eleven of 12 children with tumor progression during chemotherapy had classic medulloblastoma. After treatment, IQ scores were inferior compared with nonirradiated children from the subsequent study, HIT-SKK'92. Classic histology, metastatic disease, and male gender were independent adverse risk factors for PFS and OS in 72 children from HIT-SKK'87 and HIT-SKK'92 combined. In terms of survival, craniospinal radiotherapy was successfully delayed especially in young children with medulloblastoma of desmoplastic/extensive nodular histology, which was a strong independent favorable prognostic factor. Because of the neurocognitive deficits of survivors, the emerging concepts to avoid craniospinal radiotherapy should rely on the histological medulloblastoma subtype.