Sequential chemotherapy, high-dose thiotepa, circulating progenitor cell rescue, and radiotherapy for childhood high-grade glioma

Honey bee venom melittin increases the oxidant activity of cisplatin and kills human glioblastoma cells by stimulating the TRPM2 channel

Melittin (MLT) treatment is believed to enhance tumor cell death, apoptotic, and oxidative cytotoxic effects of cisplatin (CSP) via the modulation of Ca²⁺ channels in several cancer lines. The activation of TRPM2 mediated anticancer and CSP resistance actions via mitochondrial Ca²⁺ and Zn²⁺ accumulation-induced mitochondrial reactive free oxygen species (MitSOX) in the glioblastoma cells. The aim was to elucidate the effects of CSP and MLT combination via the TRPM2 stimulation on the tumor cell viability, cell number, cell death (propidium iodide/Hoechst rate), apoptosis, and MitSOX levels in the DBTRG-05MG cells. In the DBTRG-05MG cells, we induced four groups as control, MLT (2.5 μg/ml for 24 h), CSP (25 μM for 24 h), and CSP + MLT. The CSP-induced intracellular Ca²⁺ influxes to the TRPM2 activation were increased in the cells from coming H₂O₂ and ADP-Ribose. The influxes were decreased in the cells by the incubations of TRPM2 antagonists (ACA and carvacrol). The incubation of CSP increased the parameters of intracellular Ca²⁺ responses, mitochondria function, cytosolic free Zn²⁺ accumulation, apoptosis (caspase -3, -8, and -9), and MitSOX generation in the tumor cells. After the treatment of MLT with/without CSP, the parameters were further increased in the cells. In conclusion, the treatment of MLT increased the anticancer, tumor cell death, apoptotic, and oxidant effects of CSP in the glioblastoma tumor cells via activating the TRPM2. As a result, TRPM2 stimulation by MLT may be utilized as a successful agent in the CSP treatment of glioblastoma tumors.

How ten-years of reirradiation for paediatric high-grade glioma may shed light on first line treatment

PURPOSE

Recurrence incidence for paediatric/adolescent high-grade glioma (HGG) exceeds 80%. Reirradiation (reRT) palliates symptoms and delays further progression. Strategies for reRT are scarce: we retrospectively analysed our series to develop rational future approaches.

METHODS

We re-evaluated MRI + RT plans of 21 relapsed HGG-patients, accrued 2010-2021, aged under 18 years. All underwent surgery and RT + chemotherapy at diagnosis. Pathologic/molecular re-evaluation allowed classification based on WHO 2021 criteria in 20/21 patients. Survival analyses and association with clinical parameters were performed.

RESULTS

Relapse after 1st RT was local in 12 (7 marginal), 4 disseminated, 5 local + disseminated. Re-RT obtained 8 SD, 1 PR, 1PsPD, 1 mixed response, 10 PD; neurological signs/symptoms improved in 8. Local reRT was given to 12, followed again by 6 local (2 marginal) and 4 local + disseminated second relapses in 10/12 re-evaluated. The 4 with dissemination had 1 whole brain, 2 craniospinal irradiation (CSI), 1 spine reRT and further relapsed with dissemination and local + dissemination in 3/four assessed. Five local + disseminated tumours had 3 CSI, 1 spine reRT, further progressing locally (2), disseminated (1), n.a. (1). Three had a third RT; three were alive at 19.4, 29, 50.3 months after diagnosis. Median times to progression/survival after re-RT were 3.7 months (0.6-16.2 months)/6.9 months (0.6-17.9 months), improved for longer interval between 1st RT and re-RT (P = 0.017) and for non-PD after reRT (P < 0.001). First marginal relapse showed potential association with dissemination after re-RT (P = 0.081).

CONCLUSIONS

This is the biggest series of re-RT in paediatric HGG. Considering the dissemination observed at relapse, our results could prompt the investigation of different first RT fields in a randomized trial.

Identification of Immunological Characteristics and Immune Subtypes Based on Single-Sample Gene Set Enrichment Analysis Algorithm in Lower-Grade Glioma

Few breakthroughs have been achieved in the treatment of lower-grade glioma (LGG) in recent decades. Apart from the conventional pathological and histological classifications, subtypes based on immunogenomics would provide reference for individualized treatment and prognosis prediction. Our study identified four immunotypes of lower-grade glioma (clusters A, B, C, and D) by bioinformatics methods in TCGA-LGG and two CGGA datasets. Cluster A was an “immune-cold” phenotype with the lowest immune infiltration and longest survival expectation, whereas cluster D was an “immune-rich” subtype with the highest immune infiltration and poor survival expectation. The expression of immune checkpoints increased along with immune infiltration degrees among the clusters. It was notable that immune clusters correlated with a variety of clinical and immunogenomic factors such as age, WHO grades, IDH1/2 mutation, PTEN, EGFR, ATRX, and TP53 status. In addition, LGGs in cluster D were sensitive to cisplatin, gemcitabine, and immune checkpoint PD-1 inhibitors. RTK-RAS and TP53 pathways were affected in cluster D. Functional pathways such as cytokine–cytokine receptor interaction, antigen processing and presentation, cell adhesion molecules (CAMs), and ECM–receptor interaction were also enriched in cluster D. Hub genes were selected by the Matthews correlation coefficient (MCC) algorithm in the blue module of a gene co-expression network. Our studies might provide an immunogenomics subtyping reference for immunotherapy in LGG.

Effects of thioTEPA chemotherapy on cognition and motor coordination

Cancer survivorship has increased greatly as therapies have become more advanced and effective. Thus, we must now focus on improving the quality of life of patients after treatment. After chemotherapy, many patients experience chemotherapy-induced cognitive decline, indicating a need to investigate pathologies associated with this condition. In this study, we addressed cognitive impairment after thioTEPA treatment by assessing behavior and assaying cytokine production and the structure of dendrites in the hippocampus. Male mice were given three intraperitoneal injections of thioTEPA. Five weeks later, the mice underwent behavior testing, and brains were collected for Golgi staining and cytokine analysis. Behavior tests included y-maze and Morris water maze and licking behavioral task. Cytokines measured include: IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-10, IL-12p70, MCP-1, TNF-α, GMCSF, and RANTES. We observed decreased memory retention in behavioral tasks. Also, dendritic arborization and length were decreased after chemotherapy treatment. Finally, thioTEPA decreased cytokine production in animals treated with chemotherapy, compared to saline-treated controls. Here, we used a mouse model to correlate the decreases in dendritic complexity and inflammatory cytokine production with cognitive impairment after chemotherapy.

A microRNA profile of pediatric glioblastoma: The role of NUCKS1 upregulation

MicroRNAs (miRNAs/miRs) are a novel class of gene regulators that may be involved in tumor chemoresistance. Recently, specific miRNA expression profiles have been identified in adult glioblastoma (aGBM), but there are only limited data available on the role of miRNAs in pediatric GBM (pGBM). In the present study, the expression profile of miRNAs was examined in seven pGBMs and three human GBM cell lines (U87MG, A172 and T98G), compared with a non-tumoral pool of pediatric cerebral cortex samples by microarray analysis. A set of differentially expressed miRNAs was identified, including miR-490, miR-876-3p, miR-876-5p, miR-448 and miR-137 (downregulated), as well as miR-501-3p (upregulated). Through bioinformatics analysis, a series of target genes was predicted. In addition, similar gene expression patterns in pGBMs and cell lines was confirmed. Of note, drug resistant T98G cells had upregulated nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) expression, a protein overexpressed in many tumors that serves an important role in cell proliferation and progression. On the basis of the present preliminary report, it could be intriguing to further investigate the relationship between each of the identified differentially expressed miRNAs and NUCKS1, in order to clarify their involvement in the multi-drug resistance mechanism of pGBMs.

Marrow-ablative chemotherapy followed by tandem autologous hematopoietic cell transplantation in pediatric patients with malignant brain tumors

To improve survival in young children with malignant brain tumors, irradiation-avoiding or -minimizing marrow-ablative chemotherapy (HDCx) with autologous hematopoietic cell transplantation (AuHCT) has been investigated. We evaluated the outcome of 44 children with malignant brain tumors treated with HDCx and tandem AuHCT at Children's Hospital Los Angeles between June 1999 and July 2012. Forty-four children with malignant brain tumors were studied. Twenty-one had medulloblastoma/primitive neuro-ectodermal tumor, eight atypical teratoid/rhabdoid tumor (ATRT), five high-grade glioma, four malignant germ cell tumor, three ependymoma and three choroid plexus carcinoma. Twenty-nine patients received three tandem transplants and 15 received two tandem transplants, respectively. The 5-year PFS and overall survivals (OS) for all patients were 46.3±8.2% and 51.7±8.5%, respectively. The PFS and OS for 27 newly diagnosed patients were 68.9±9.9% and 73.5±9.3%, respectively, compared with 17 transplanted at relapse 11.8±9.8% (P<0.001) and 15.1±12.3% (P=0.0231), respectively. The 5-year PFS and OS in 13 previously unirradiated patients were 74±13% and 74±13% versus 33.2±9.8% and 40.2±10.6% in 31 irradiated patients (P=0.11 and P=0.239), respectively. One patient died of transplant-related toxicity. HDCx with tandem AuHCT is feasible and safe in children with malignant brain tumors with encouraging irradiation-free survival in newly diagnosed children.

Pediatric high-grade glioma: current molecular landscape and therapeutic approaches

High-grade pediatric central nervous system glial tumors are comprised primarily of anaplastic astrocytomas (AA, WHO grade III) and glioblastomas (GBM, WHO grade IV). High-grade gliomas are most commonly diagnosed in the primary setting in children, but as in adults, they can also arise as a result of transformation of a low-grade malignancy, though with limited frequency in the pediatric population. The molecular genetics of high-grade gliomas in the pediatric population are distinct from their adult counterparts. In contrast to the adult population, high-grade gliomas in children are relatively infrequent, representing less than 20% of cases.

A systematic review of overall survival in pediatric primary glioblastoma multiforme of the spinal cord

OBJECTIVE The incidence of primary spinal cord glioblastoma multiforme (GBM) in the pediatric age group is very rare. Only a few case series and case reports have been published in the literature; therefore, overall survival (OS) outcome and the as-yet poorly defined management options are not discussed in detail. The authors performed a cumulative survival analysis of all reported cases of pediatric spinal cord GBM to identify the predictive factors related to final survival outcome. METHODS A comprehensive search for relevant articles was performed on PubMed's electronic database MEDLINE for the period from 1950 to 2015 using the search words "malignant spinal cord tumor" and "spinal glioblastoma multiforme." This study was limited to patients younger than 18 years of age. Survival rates for children with various tumor locations and treatments were collected from the published articles and analyzed. RESULTS After an extensive literature search, 29 articles met the study inclusion criteria. From the detailed information in these articles, the authors found 53 children eligible for the survival analysis. The majority (45%) of the children were more than 12 years old. Thirty-four percent of the cases were between 7 and 12 years of age, and 21% were younger than 7 years. In the Kaplan-Meier survival analysis, children younger than 7 years of age had better survival (13 months) than the children older than 7 years (7-12 years: 10 months, > 12 years: 9 months; p = 0.01, log-rank test). Fifty-five percent of the children were female and 45% were male. A cervical tumor location (32%) was the most common, followed by thoracic (28.3%). Cervicothoracic (18.9%) and conus (18.8%) tumor locations shared the same percentage of cases. Cervical tumors had a worse outcome than tumors in other locations (p = 0.003, log-rank test). The most common presenting symptom was limb weakness (53%), followed by sensory disturbances (25%). Median OS was 10 months. The addition of adjuvant therapy (radiotherapy [RT] and/or chemotherapy [CT]) after surgery significantly improved OS (p = 0.01, log-rank test). Children who underwent gross-total resection and RT had better outcomes than those who underwent subtotal resection and RT (p = 0.04, log-rank test). Cerebrospinal fluid spread, hydrocephalus, brain metastasis, and spinal metastasis were not correlated with OS in primary spinal GBM. CONCLUSIONS Adjuvant therapy after surgery had a beneficial effect on overall outcome of spinal GBM in the pediatric age group. Gross-total resection followed by RT produced a better outcome than subtotal resection with RT. Further large-scale prospective study is required to establish the genetic and molecular factors related to OS in primary GBM of the spinal cord in pediatric patients.

Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for High-Grade Gliomas in Children and Adolescents

With the aim to investigate the outcome of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) for high-grade gliomas (HGGs), we retrospectively reviewed the medical records of 30 patients with HGGs (16 glioblastomas, 7 anaplastic astrocytomas, and 7 other HGGs) between 2006 and 2015. Gross or near total resection was possible in 11 patients. Front-line treatment after surgery was radiotherapy (RT) in 14 patients and chemotherapy in the remaining 16 patients including 3 patients less than 3 years of age. Eight of 12 patients who remained progression free and 5 of the remaining 18 patients who experienced progression during induction treatment underwent the first HDCT/auto-SCT with carboplatin + thiotepa + etoposide (CTE) regimen and 11 of them proceeded to the second HDCT/auto-SCT with cyclophosphamide + melphalan (CyM) regimen. One patient died from hepatic veno-occlusive disease (VOD) during the second HDCT/auto-SCT; otherwise, toxicities were manageable. Four patients in complete response (CR) and 3 of 7 patients in partial response (PR) or second PR at the first HDCT/auto-SCT remained event free: however, 2 patients with progressive tumor experienced progression again. The probabilities of 3-year overall survival (OS) after the first HDCT/auto-SCT in 11 patients in CR, PR, or second PR was 58.2% ± 16.9%. Tumor status at the first HDCT/auto-SCT was the only significant factor for outcome after HDCT/auto-SCT. There was no difference in survival between glioblastoma and other HGGs. This study suggests that the outcome of HGGs in children and adolescents after HDCT/auto-SCT is encouraging if the patient could achieve CR or PR before HDCT/auto-SCT.

Molecular characterization of paediatric glioneuronal tumours with neuropil-like islands: a genome-wide copy number analysis

Paediatric glioneuronal tumour with neuropil-like islands (GTNI) is a rare neoplasm of neuronal differentiation and diffusely infiltrating astroglial and oligodendrocyte-like components. The 2007 World Health Organization classification of central nervous system tumours considered it as a pattern variation of anaplastic astrocytoma. There are few data on paediatric GTNI probably both for their rarity and variable clinical aggressiveness. We studied by SNP/CGH array four tumour samples of GTNI from two males and two females (one new-born and three children aged from 4 to 8 years), in order to identify any possible common genomic alteration. All patients received chemo- and radiotherapy after their surgical treatment. No genomic instability nor recurrent alterations have been demonstrated in two of our GTNI cases. In the remaining two, we detected a mosaic trisomy 8 (15-20%) in one case, and an amplification at 5q14.1 involving DMGDH (partially), BHMT2 and BHMT genes, with the distal breakpoint falling at 23 Kbp from the 5'UTR of JMY, a p53 cofactor. Although the smallness of the sample impairs any clinical-histological correlation, GTNI appear different at the molecular level, with genomic imbalances playing a possible role in at least part of them. Our work gives an important contribution in knowledge and classification of this family of tumours.

Blood-brain barrier, cytotoxic chemotherapies and glioblastoma

INTRODUCTION

Glioblastomas (GBM) are the most common and aggressive primary malignant brain tumors in adults. The blood brain barrier (BBB) is a major limitation reducing efficacy of anti-cancer drugs in the treatment of GBM patients. Areas covered: Virtually all GBM recur after the first-line treatment, at least partly, due to invasive tumor cells protected from chemotherapeutic agents by the intact BBB in the brain adjacent to tumor. The passage through the BBB, taken by antitumor drugs, is poorly and heterogeneously documented in the literature. In this review, we have focused our attention on: (i) the BBB, (ii) the passage of chemotherapeutic agents across the BBB and (iii) the strategies investigated to overcome this barrier. Expert commentary: A better preclinical knowledge of the crossing of the BBB by antitumor drugs will allow optimizing their clinical development, alone or combined with BBB bypassing strategies, towards an increased success rate of clinical trials.

Glioblastoma multiforme in a child with tuberous sclerosis complex

Tuberous Sclerosis Complex (TSC) is characterized by the presence of benign tumors in the brain, kidneys, heart, eyes, lungs, and skin. The typical brain lesions are cortical tubers, subependimal nodules and subependymal giant-cell astrocytomas. The occurrence of malignant astrocytomas such as glioblastoma is rare. We report on a child with a clinical diagnosis of TSC and a rapidly evolving glioblastoma multiforme. Genetic analysis identified a de novo mutation in TSC2. Molecular characterization of the tumor was performed and discussed, as well as a review of the literature where cases of TSC and glioblastoma multiforme are described. Although the co-occurrence of TSC and glioblastoma multiforme seems to be rare, this possible association should be kept in mind, and proper clinical and radiological follow up should be recommended in these patients.

Optimal Timing of Whole-Brain Radiation Therapy Following Craniotomy for Cerebral Malignancies

BACKGROUND

For patients with cerebral metastases that are limited in number, surgical resection followed by whole-brain radiation therapy is the standard of care. In addition, for high-grade gliomas, maximal surgical resection followed by local radiotherapy is considered the optimal treatment. Radiation is known to impair wound healing, including healing of surgical incisions. Radiotherapy shortly after surgical resection would be expected to minimize the opportunity for tumor regrowth or progression. Owing to these competing interests, the purpose of this study was to shed light on the optimal timing of radiotherapy after surgical resection of brain metastasis or high-grade gliomas.

METHODS

A review of the literature was conducted on the following topics: radiation and wound healing, corticosteroid use and wound healing, radiotherapy for tumor control for cerebral metastases and high-grade gliomas, and whole-brain radiation therapy or focal radiotherapy after craniotomy with focus on the timing of radiotherapy after surgery.

RESULTS

In animal models, wound integrity and healing was less impaired by radiotherapy administered 1 week after surgery. In humans, this timing would be expected to be significantly longer, on the order of several weeks.

CONCLUSIONS

Given the limited literature, insufficient conclusions can be drawn. However, animal data suggest a period of at least 1 week (but it is likely several weeks in humans) is necessary for reconstitution of wound strength before initiation of radiation therapy. A randomized prospective study is recommended to understand better the effect of the timing of radiation therapy following surgical intervention for brain metastasis or high-grade gliomas.

Pediatric supratentorial high-grade glioma: multicenter retrospective observational study of the Korean Society for Pediatric Neuro-Oncology

We analyzed the prognostic factors of Korean pediatric patients with supratentorial high-grade glioma (HGG). Between 1997 and 2011, 62 patients with 34 glioblastomas and 28 anaplastic gliomas were surgically operated at nine institutions. The male-to-female ratio was 33 to 29 and the median age was 12 years (range 1-18). The prognostic significance of tumor location, extent of removal, pathologic grade, treatment method, and pattern of recurrence was analyzed. The median progression-free survival (PFS) and overall survival (OS) were 9.3 (± 0.8) and 17.8 (± 1.9) months, respectively. Glioblastoma and anaplastic glioma showed OSs of 15.9 (± 1.3) and 19.6 (± 2.4) months, respectively. Based on the univariate analysis, gross total removal (GTR) and initial combined chemoradiotherapy improved PFS (p = 0.012 and p = 0.003) and OS (p = 0.030 and p = 0.013), respectively. Cerebrospinal fluid (CSF) dissemination showed poor OS (p = 0.001). Based on the multivariate analysis, GTR and initial combined chemoradiotherapy resulted in an improved PFS [(hazard ratio 0.360; 95 % CI 0.177-0.733; p = 0.005) and (hazard ratio 0.458; 95 % CI 0.230-0.911; p = 0.026), respectively]. GTR, initial combined chemoradiotherapy, and no CSF seeding resulted in an improved OS [(hazard ratio 0.417; 95 % CI 0.201-0.861; p = 0.018), (hazard ratio 0.406; 95 % CI 0.206-0.800; p = 0.009), and (hazard ratio 0.288; 95 % CI 0.148-0.563; p = 0.000), respectively]. No significant difference in PFS and OS was observed between glioblastoma and anaplastic glioma. CSF dissemination was observed in 22 patients (35.5 %) during total follow-up. Pediatric anaplastic glioma showed poor survival, similarly to glioblastoma. GTR and initial combined chemoradiotherapy were associated with improved survival.

Management of high-grade gliomas in the pediatric patient: Past, present, and future

High-grade gliomas (HGGs) constitute ∼15% of all primary brain tumors in children and adolescents. Routine histopathological diagnosis is based on tissue obtained from biopsy or, preferably, from the resected tumor itself. The majority of pediatric HGGs are clinically and biologically distinct from histologically similar adult malignant gliomas; these differences may explain the disparate responses to therapy and clinical outcomes when comparing children and adults with HGG. The recently proposed integrated genomic classification identifies 6 distinct biological subgroups of glioblastoma (GBM) throughout the age spectrum. Driver mutations in genes affecting histone H3.3 (K27M and G34R/V) coupled with mutations involving specific proteins (TP53, ATRX, DAXX, SETD2, ACVR1, FGFR1, NTRK) induce defects in chromatin remodeling and may play a central role in the genesis of many pediatric HGGs. Current clinical practice in pediatric HGGs includes surgical resection followed by radiation therapy (in children aged > 3 years) with concurrent and adjuvant chemotherapy with temozolomide. However, these multimodality treatment strategies have had a minimal impact on improving survival. Ongoing clinical trials are investigating new molecular targets, chemoradiation sensitization strategies, and immunotherapy. Future clinical trials of pediatric HGG will incorporate the distinction between GBM molecular subgroups and stratify patients using group-specific biomarkers.

Genome-wide copy number analysis in pediatric glioblastoma multiforme

Glioblastoma (GBM) is a very aggressive and lethal brain tumor with poor prognosis. Despite new treatment strategies, patients' median survival is still less than 1 year in most cases. Few studies have focused exclusively on this disease in children and most of our understanding of the disease process and its clinical outcome has come from studies on malignant gliomas in childhood, combining children with the diagnosis of GBM with other pediatric patients harboring high grade malignant tumors other than GBM. In this study we investigated, using array-CGH platforms, children (median age of 9 years) affected by GBM (WHO-grade IV). We identified recurrent Copy Number Alterations demonstrating that different chromosome regions are involved, in various combinations. These observations suggest a condition of strong genomic instability. Since cancer is an acquired disease and inherited factors play a significant role, we compared for the first time the constitutional Copy Number Variations with the Copy Number Alterations found in tumor biopsy. We speculate that genes included in the recurrent 9p21.3 and 16p13.3 deletions and 1q32.1-q44 duplication play a crucial role for tumorigenesis and/or progression. In particular we suggest that the A2BP1 gene (16p13.3) is one possible culprit of the disease. Given the rarity of the disease, the poor quality and quantity of bioptic material and the scarcity of data in the literature, our findings may better elucidate the genomic background of these tumors. The recognition of candidate genes underlying this disease could then improve treatment strategies for this devastating tumor.

Treatment of children with glioblastoma with conformal radiation, temozolomide, and bevacizumab as adjuncts to surgical resection

Prognosis for children with glioblastoma is unacceptably poor. Modest improvements in progression-free survival were seen in adults with glioblastoma by combining temozolomide and bevacizumab with conformal radiation. We retrospectively reviewed 3 cases of glioblastoma in children treated using upfront bevacizumab and temozolomide during radiation, followed by 12 cycles of maintenance therapy. All patients completed therapy with minimal toxicity and no delays in treatment. Two patients remain disease free at 38 and 49 months from diagnosis. One patient recurred 14 months off therapy and currently receives salvage therapy 48 months from diagnosis. These results support further investigation of this regimen.

Pediatric glioma stem cells: biologic strategies for oncolytic HSV virotherapy

While glioblastoma multiforme (GBM) is the most common adult malignant brain tumor, GBMs in childhood represent less than 10% of pediatric malignant brain tumors and are phenotypically and molecularly distinct from adult GBMs. Similar to adult patients, outcomes for children with high-grade gliomas (HGGs) remain poor. Furthermore, the significant morbidity and mortality yielded by pediatric GBM is compounded by neurotoxicity for the developing brain caused by current therapies. Poor outcomes have been attributed to a subpopulation of chemotherapy and radiotherapy resistant cells, termed “glioma stem cells” (GSCs), “glioma progenitor cells,” or “glioma-initiating cells,” which have the ability to initiate and maintain the tumor and to repopulate the recurring tumor after conventional therapy. Future innovative therapies for pediatric HGG must be able to eradicate these therapy-resistant GSCs. Oncolytic herpes simplex viruses (oHSV), genetically engineered to be safe for normal cells and to express diverse foreign anti-tumor therapeutic genes, have been demonstrated in preclinical studies to infect and kill GSCs and tumor cells equally while sparing normal brain cells. In this review, we discuss the unique aspects of pediatric GSCs, including markers to identify them, the microenvironment they reside in, signaling pathways that regulate them, mechanisms of cellular resistance, and approaches to target GSCs, with a focus on the promising therapeutic, genetically engineered oHSV.

Central nervous system tumors

Central nervous system tumors are the most frequent malignant tumor in children and the main cause of death in this age group after traffic accidents. The current estimates are that one adult in 2500 is a survivor of a brain tumor that occurred during childhood. These tumors are particularly heterogeneous in terms of histology/biology, treatment, and outcome. They share, however, a high risk of neurological and cognitive morbidity due to the disease itself and the treatment modalities (radiotherapy, surgery, and chemotherapy). Diagnosis is frequently delayed because symptoms are usually nonspecific at the beginning of the evolution. Posterior fossa is the most frequent site and the tumors present most frequently with signs of intracranial hypertension. Supratentorial tumors are more frequent in infants and in adolescents; seizures are not uncommon, especially for benign tumors. When adjuvant treatment is needed, radiotherapy is usually the mainstay apart from some histologies where chemotherapy may be sufficient: low-grade gliomas, desmoplastic medulloblastomas, malignant glial tumors in infants. Multidisciplinary care is best performed in tertiary care centers and should include early rehabilitation programs soon after surgery.

Chemotherapy drug thioTEPA exacerbates stress-induced anhedonia and corticosteroid responses but not impairment of hippocampal cell proliferation in adult mice

Cancer patients often suffer long-lasting affective and cognitive impairments as a result of chemotherapy treatment. Previous work in our lab has shown deficits in learning and memory and hippocampal cell proliferation in mice lasting up to 20 weeks following acute administration of thioTEPA. In this study, the effects of thioTEPA in conjunction with effects of chronic stress on depression-related behavior were examined in C57BL/6J mice, 12 weeks following thioTEPA administration. Chemotherapy-treated mice showed a diminished sucralose preference compared to controls that was further exacerbated after 2 weeks of daily restraint stress. This intensifying effect was not observed in the Porsolt forced swim test. Moreover, stress-induced corticosteroid responses were exaggerated in thioTEPA-treated mice. Cell proliferation in the dentate gyrus of the hippocampus was also impaired similarly by prior thioTEPA treatment and by daily restraint stress, with no additive effect. Results suggest that some depression-related impairments may be exacerbated by chemotherapy treatment through altered corticosteroid regulation.

Glioneuronal tumor with neuropil-like islands: clinical, morphologic, immunohistochemical, and molecular features of three pediatric cases

Glioneuronal tumors with neuropil-like islands are rare. The 1st reported cases were localized in the cerebral hemispheres of adults, showed homogeneous histopathologic features (infiltrating astrocytic growth and neuropil-like islands rimmed by neuronal cells), and had an unfavorable behavior. We report 3 pediatric cases (1 boy and 2 girls, ages 4, 6, and 8 years, respectively). The boy had a cerebral tumor, and the girls had a spinal tumor. The younger girl also had multiple posterior fossa lesions. The boy and older girl underwent a gross total resection. The younger girl underwent a subtotal resection of the spinal tumor; posterior fossa lesions were not surgically treated. The boy and younger girl are in complete remission at 33 and 24 months, respectively, after surgery and subsequent high-dose chemoradiotherapy. The older girl had a recurrence that was partially resected. Afterward, she started high-dose chemoradiotherapy and had an optimal radiologic response at 4 months follow up. Microscopically, the common denominator was the presence of synaptophysin-positive neuropil-like islands. One tumor showed ependymal features (pseudorosettes and punctate epithelial membrane antigen immunopositivity). Two tumors had 1p deletion. 19q deletion, MGMT gene promoter methylation, EGFR amplifications or polysomy, and EGFR, IDH1, IDH2, and TP53 genes mutation analyses yielded negative results. In conclusion, glioneuronal tumor with neuropil-like islands can affect children, arise in the spinal cord, and show ependymal features in its glial component. A high-dose chemoradiotherapy program is effective.

High-grade gliomas in children

High-grade gliomas (HGGs) are malignant tumors and typically include glioblastoma multiforme and anaplastic astrocytoma subtypes. Brainstem gliomas and ependymomas are separate entities with respect to clinical presentation, treatment, prognosis, and outcome in comparison with supratentorial HGGs. In children, these tumors account for 3% to 7% of newly diagnosed brain tumors and 20% of all diagnoses of pediatric supratentorial brain tumors. These neoplasms are highly proliferative and mitotically active and of glial origin. This article reviews clinical, diagnostic, and pathologic features of HGG and current treatments and potential future therapies specific to pediatric patients with HGGs.

Pediatric primary intramedullary spinal cord glioblastoma

Spinal cord tumors in pediatric patients are rare, representing less than 1% of all central nervous system tumors. Two cases of pediatric primary intramedullary spinal cord glioblastoma at ages 14 and 8 years are reported. Both patients presented with rapid onset paraparesis and quadraparesis. Magnetic resonance imaging in both showed heterogeneously enhancing solitary mass lesions localized to lower cervical and upper thoracic spinal cord parenchyma. Histopathologic diagnosis was glioblastoma. Case #1 had a small cell component (primitive neuroectodermal tumor-like areas), higher Ki67, and p53 labeling indices, and a relatively stable karyotype with only minimal single copy losses involving regions: Chr8;pter-30480019, Chr16;pter-29754532, Chr16;56160245–88668979, and Chr19;32848902-qter on retrospective comparative genomic hybridization using formalin-fixed, paraffin-embedded samples. Case #2 had relatively bland histomorphology and negligible p53 immunoreactivity. Both underwent multimodal therapy including gross total resection, postoperative radiation and chemotherapy. However, there was no significant improvement in neurological deficits, and overall survival in both cases was 14 months.This report highlights the broad histological spectrum and poor overall survival despite multi modality therapy. The finding of relatively unique genotypic abnormalities resembling pediatric embryonal tumors in one case may highlight the value of genome-wide profiling in development of effective therapy. The differences in management with intracranial and low-grade spinal cord gliomas and current management issues are discussed.

Is there a role for myeloablative chemotherapy with autologous hematopoietic cell rescue in the management of childhood high-grade astrocytomas?

High-grade or malignant glioma represent 10% of pediatric brain tumors and are, taken as a whole, the second more frequent malignant histotype after medulloblastoma. Apart from a complete excision followed by full dose local radiotherapy, chemotherapy seems to give some beneficial to final outcome. Different trials have explored the role of high-dose chemotherapy that theoretically could give an advantage to these patients by overcoming blood-brain barrier, tumor cell chemo-resistance and inducing a wider number of responses. It is, however, still doubtful if better responses translate into improved outcome and which patients can have a true beneficial from this treatment strategy.

Adjuvant dendritic cell-based tumour vaccination for children with malignant brain tumours

BACKGROUND

A large experience with dendritic cell (DC)-based vaccination for malignant brain tumours has been gained in adults. Here we focus on the results obtained in children with relapsed malignant brain tumours.

PROCEDURE

In total 45 children were vaccinated: 33 high grade glioma (HGG), 5 medulloblastoma (MB)/primitive neuro-ectodermal tumour (PNET), 4 ependymoma and 3 atypical teratoid-rhabdoid tumour (ATRT). Autologous, monocyte-derived DC were generated and loaded with tumour lysate, which was used as source of tumour-associated antigens.

RESULTS

In 38 patients peripheral blood mononuclear cells (PBMC) were obtained from leukapheresis and in 7 patients from fresh blood samples. 7 HGG patients are still alive with median follow-up (FU) of 35.7 months (range: 12.1-85.6). Median overall survival (OS) was 13.5 months (range: 1.4-85.6). All patients with MB/PNET died (median OS 5.7 months; range 4.3-51.2). One patient with ependymoma is still alive at 22.3 months FU. The other three patients died at, respectively, 7.7, 30.1 and 31.5 months. Two patients with ATRT are still alive at, respectively, 34.1 and 52.6 months FU. The third patient died at 50.5 months. No severe adverse events were noticed.

CONCLUSIONS

In this exploratory study, HGG and ATRT seem to respond more favourably to vaccination than MB/PNET and ependymoma. Although preliminary, our results are promising and support further testing of DC-based immunotherapy in new treatment protocols for HGG and ATRT.

Intensive chemotherapy improves survival in pediatric high-grade glioma after gross total resection: results of the HIT-GBM-C protocol

BACKGROUND

The authors hypothesized that intensified chemotherapy in protocol HIT-GBM-C would increase survival of pediatric patients with high-grade glioma (HGG) and diffuse intrinsic pontine glioma (DIPG).

METHODS

Pediatric patients with newly diagnosed HGG and DIPG were treated with standard fractionated radiation and simultaneous chemotherapy (cisplatin 20 mg/m2 x 5 days, etoposide 100 mg/m2 x 3 days, and vincristine, and 1 cycle of cisplatin + etoposide + ifosfamide 1.5 g/m x 5 days [PEI] during the last week of radiation). Subsequent maintenance chemotherapy included further cycles of PEI in Weeks 10, 14, 18, 22, 26, and 30, followed by oral valproic acid.

RESULTS

Ninety-seven (pons, 37; nonpons, 60) patients (median age, 10 years; grade IV histology, 35) were treated. Resection was complete in 21 patients, partial in 29, biopsy only in 26, and not performed in 21. Overall survival rates were 91% (standard error of the mean [SE] +/- 3%), 56%, and 19% at 6, 12, and 60 months after diagnosis, respectively. When compared with previous protocols, there was no significant benefit for patients with residual tumor, but the 5-year overall survival rate for patients with complete resection treated on HIT-GBM-C was 63% +/- 12% SE, compared with 17% +/- 10% SE for the historical control group (P = .003, log-rank test).

CONCLUSIONS

HIT-GBM-C chemotherapy after complete tumor resection was superior to previous protocols.

The chemotherapy agent, thioTEPA, yields long-term impairment of hippocampal cell proliferation and memory deficits but not depression-related behaviors in mice

ThioTEPA is a chemotherapeutic agent used in the treatment of cancers, and more recently has been proposed as a component of high-dose therapy for young patients with recurrent malignant brain tumors. We previously demonstrated a significant dose-dependent reduction of cell proliferation in the dentate gyrus of the hippocampus in mice immediately following a 3-day regiment of thioTEPA. The aim of this study was to evaluate the long-term effects of thioTEPA treatment on hippocampal cell proliferation and potential effects on memory deficit or depression-related behavior in C57BL/6J mice. A 3-day regimen of thioTEPA (10mg/kg/d, i.p.) yielded a significant reduction in cell proliferation immediately after treatment as assessed by BrdU incorporation, and none of the labeled progeny that initially survived the treatment were detectable one week later. Following a 3-week rebound in proliferation following treatment, a significant deficit in proliferation reappeared and persisted for at least 21 weeks following treatment. ThioTEPA-treated mice subjected to an object recognition test 1, 2, 3, 4, 8, 12, 20 or 30 weeks following treatment demonstrated significant memory deficits at 12 and 20 weeks. Mice demonstrated a similar deficit in an object placement test when tested 20 weeks following thioTEPA treatment. However, no observable effects on performance in the Porsolt forced swim test or the tail suspension test were observed in thioTEPA-treated mice. Together, these studies suggest that cumulative long-term negative effects of thioTEPA treatment on proliferation of new cells in the dentate gyrus may contribute to cognitive impairments associated with its use in the treatment of cancer.

Congenital glioblastoma

We describe the case a 2-day-old female with congenital glioblastoma. Total resection was followed by adjuvant and high dose chemotherapy, as indicated by the current Italian infant protocol. The child is alive and well 18 months after diagnosis. A review of 67 selected congenital brain tumors showed the mortality rate was 82%. Even though the majority of patients had glioblastoma, only 5/67 had received adjuvant therapy. To ensure optimal outcomes, we recommend total or subtotal surgical resection, followed by adjuvant and high dose chemotherapy. Given the lack specific protocols for congenital brain tumors an international consensus seems to be needed, starting with congenital glioblastoma.

Pediatric brain tumors: mutations of two dioxygenases (hABH2 and hABH3) that directly repair alkylation damage

Alkylating agents, commonly used for brain tumor therapy, induce DNA and RNA lesions that, if not repaired, drive cells to apoptosis. Thus, cellular mechanisms that are responsible for nucleic acid repair are possibly involved in drug resistance. This work analyzes hABH2 and hABH3, two human Fe(II)-dependent dioxygenases in pediatric brain tumors that are treated with alkylating agents. We analyzed 25 brain tumor samples for hABH2 and hABH3 mutations; a subset of samples was tested for quantitative expression with Real-Time PCR. Sequencing analysis showed two new mutations in two glioma patients, one of hABH2 coding sequence (I141 V) and the other of hABH3 (D189 N). The mutation at codon 189 falls in a crucial region of the protein. All subjects analyzed by Real-Time PCR showed an enhanced expression of the two genes, particularly of hABH2. This is the first study of hABH2 and hABH3 in pediatric brain tumors; further molecular investigations of their mutations and expression may help determine their role in response to chemotherapy.

Hyperfractionated Accelerated Radiotherapy in the Milan Strategy for Metastatic Medulloblastoma

Purpose

With a view to improving the prognosis for patients with metastatic medulloblastoma, we tested the efficacy and toxicity of a hyperfractionated accelerated radiotherapy (HART) regimen delivered after intensive sequential chemotherapy.

Patients and Methods

Between 1998 and 2007, 33 consecutive patients received postoperative methotrexate (8 g/m2), etoposide (2.4 g/m2), cyclophosphamide (4 g/m2), and carboplatin (0.8 g/m2) in a 2-month schedule, then HART with a maximal dose to the neuraxis of 39 Gy (1.3 Gy/fraction, 2 fractions/d) and a posterior fossa boost up to 60 Gy (1.5 Gy/fraction,2 fractions/d). Patients with persistent disseminated disease before HART were consolidated with two myeloablative courses and circulating progenitor cell rescue.

Results

Patients were classified as having M1 (n = 9), M2 (n = 6), M3 (n = 17), and M4 (n = 1) disease. Seven patients younger than 10 years old who achieved complete response after chemotherapy received a lower dose to the neuraxis (31.2 Gy). Twenty-two of the 32 assessable patients responded to chemotherapy; disease was stable in five patients and progressed in five patients. One septic death occurred before radiotherapy. Eight patients experienced relapse after a median of 12 months. Fourteen of the 33 patients underwent consolidation therapy after HART. With a median 82-month survivor follow-up, the 5-year event-free, progression-free, and overall survival rates were 70%, 72%, and 73%, respectively. No severe clinical complications of HART have emerged so far.

Conclusion

HART after intensive postoperative chemotherapy, followed by myeloablative chemotherapy in selected cases, proved feasible in children with metastatic medulloblastoma. The results of our treatment compare favorably with other series treated using conventional therapies.

MDR1 (ABCB1) G1199A (Ser400Asn) polymorphism alters transepithelial permeability and sensitivity to anticancer agents

PURPOSE

P-glycoprotein (P-gp), encoded by MDR1 (or ABCB1), is important in anticancer drug delivery and resistance. We evaluated alterations in P-gp-mediated transport of anticancer agents due to the MDR1 G1199A polymorphism.

METHODS

Using stable recombinant epithelial cells expressing wild-type (MDR1 (wt)) or G1199A (MDR1 (1199A)), anticancer drug sensitivity and transepithelial permeability were evaluated.

RESULTS

The recombinant cells MDR1 (wt) and MDR1 ( 1199A ) displayed comparable doxorubicin resistance. However, MDR1 (1199A) cells displayed greater resistance to vinblastine, vincristine, paclitaxel, and VP-16 (11-, 2.9-, 1.9-, and 2.9-fold, respectively). Alterations in transepithelial permeability paralleled these changes. Efflux of doxorubicin was similar between MDR1 wt - and MDR1 (1199A)-expressing cells, while P-gp-mediated transport was greater for vinblastine and vincristine in MDR1 (1199A) cells (2.9- and 2.0-fold, respectively).

CONCLUSIONS

The occurrence and magnitude of the MDR1 G1199A effect is drug specific. Overall, the MDR1 G1199A polymorphism may impact anticancer efficacy through modulation of drug distribution and delivery to target tumor cells.

Anaplastic oligodendroglioma after childhood acute lymphoblastic leukemia: chemotherapy and autologous peripheral blood stem cell transplantation

Secondary brain tumors after cranial irradiation occur in survivors of childhood acute lymphoblastic leukemia (ALL). We report a case of anaplastic oligodendroglioma with recurrence occurring in a 15-year-old girl, 8 years after the diagnosis of ALL. She was treated with cisplatin, vincristine, etoposide, and ifosfamide followed by cranial irradiation with good response. However, as new lesions appeared out of the radiation field and then multiple lesions after she stopped the chemotherapy, she was treated with procarbazine, CCNU, and vincristine followed by autologous peripheral blood stem cell transplantation with preconditioning of carboplatin, thiotepa, and etoposide. She showed no evidence of disease for 3 years after last recurrence. High-dose chemotherapy with stem cell rescue seems to be potentially effective for multiple recurrent anaplastic oligodendroglioma occurring after childhood ALL.

Diffuse pontine gliomas in children: changing strategies, changing results? A mono-institutional 20-year experience

Patients with diffuse pontine gliomas have a median survival of less than one year and represent a challenge for pediatric oncologists, prompting them to attempt experimental therapies. From 1987 to 2005, 62 children with diffuse pontine glioma, not amenable to curative surgery, were treated according to four successive pilot protocols: (1) concomitant chemo-radiotherapy (etoposide, cytarabine, ifosfamide, cisplatin, and dactinomycin); (2) intensive high-dose courses chemotherapy (cisplatin/etoposide, cyclophosphamide/vincristine/methotrexate) and a subsequent course of myeloablative thiotepa followed by radiation and maintenance chemotherapy; (3) cisplatin/etoposide followed by isotretinoin before, during and after focal irradiation; and (4) iv vinorelbine before, during, and after irradiation. Considering all patients, 77% experienced a transient response to treatment, always detectable after radiotherapy. The progression-free survival (PFS) rate was 25 +/- 6% at one year, median PFS was seven months; overall survival (OS) was 45 +/- 6%, median OS was eleven months: no statistical differences in the four studies in terms of outcome were detected. Despite improved diagnostic, therapeutic, and supportive tools in pediatric neuro-oncology, little has been achieved for patients with diffuse pontine tumors.

Pattern of recurrence in paediatric malignant glioma: an institutional experience

BACKGROUND

The purpose of this retrospective study was to investigate the pattern of recurrence in paediatric malignant gliomas.

MATERIAL AND METHODS

We reviewed the notes, diagnostic imaging and treatment charts of 30 consecutive paediatric patients (age less than 18 years at diagnosis, range 0.5-17 years) presenting with a malignant glioma presenting to the paediatric oncology unit at the Royal Marsden Hospital over a 10-year period. The imaging at the time of first relapse was compared with the initial diagnostic scans to define a relapse as local, marginal or distant.

RESULTS

Median follow-up was 13 months (range 1-99 months). Twenty-four of 30 patients (80%) showed evidence of progression with a median time to progression of 8.5 months (range 3-64 months). Thirteen out of 24 patients developed local or marginal recurrences while 11/24 patients recurred at distant sites as site of first relapse (46%).

CONCLUSION

Our series suggests that the pattern of relapses in paediatric malignant gliomas could be different from that reported in adult studies as we observed a significant incidence of distant relapses. Larger prospective series need to be conducted to investigate the clinico-biological characteristics of the population at high risk for leptomeningeal dissemination.

Temozolomide after radiotherapy for newly diagnosed high-grade glioma and unfavorable low-grade glioma in children

Chemotherapy is commonly used in the treatment of children with high-grade glioma, although its usefulness is uncertain. We conducted a multi-institutional study to evaluate the efficacy of temozolomide given after radiotherapy in children with newly diagnosed high-grade glioma and unfavorable low-grade glioma (gliomatosis cerebri or bithalamic involvement). Optional window therapy of intravenous irinotecan (10 doses of 20 mg/m2 per cycle x 2) was given over 6 weeks. The 5-day schedule of temozolomide (200 mg/m2 per day) started 4 weeks after the completion of radiotherapy and continued for a total of 6 cycles. Thirty-one eligible patients (median age: 12.3 years) participated. Tumors most commonly involved cerebral hemispheres (n = 13, 42%) and thalamus (n = 14, 45%). Whereas six patients underwent radical resection, the remainder had limited surgery, including biopsy (n = 14, 45%). The predominant histologic diagnoses were glioblastoma multiforme (n = 15, 48%) and anaplastic astrocytoma (n = 10, 32%). Two patients had bithalamic grade II astrocytoma. Twenty-seven patients received radiotherapy (median dose: 59.4 Gy), including craniospinal irradiation in 3 because of leptomeningeal spread. Four patients did not receive radiotherapy in this study because of consent withdrawn (n = 2), toxicity during window therapy (n = 1), or at the physician's discretion (n = 1). Twenty-three patients received 112 cycles of temozolomide therapy. The 2-year progression-free and overall survival estimates were 11 +/- 5% and 21 +/- 7%, respectively. Although the heterogeneity of prognostic factors in our patients made assessment of treatment outcome more difficult, the addition of 6 cycles of temozolomide after radiotherapy did not seem to alter the poor outcome of these patients.

Use of high-dose chemotherapy in front-line therapy of childhood malignant glioma

Brain tumors are the second most common cancer in pediatric patients and the main cause from death of malignant tumors in this age group. High-grade or malignant glioma, among which anaplastic astrocytomas and glioblastoma are the most prevalent histotypes, represent 10% of pediatric brain tumors and, taken as a whole, are the second most frequent malignant histotype after medulloblastoma. Apart from complete excision followed by full-dose local radiotherapy, chemotherapy appears to provide some benefit to the final outcome. Different trials have explored the role of high-dose chemotherapy that, theoretically, could give an advantage to these patients by overcoming the blood-brain barrier, cell chemoresistance and inducing a wider number of responses. However, it is still doubtful if more responses translate into better outcome and it is not fully understood which patients can experience a true benefit from this treatment strategy. New protocols under evaluation include new agents with specific biological targets, multiple cycles of high-dose chemotherapy, and vaccination, as an immunotherapeutic approach.

A Case of Relapsing Glioblastoma Multiforme Responding to Vinorelbine

Childhood malignant gliomas are rare and their clinical behavior is almost as aggressive as in adults: they resist treatment, progress rapidly and often spread. Therapeutic strategies at relapse deserve an experimental approach, since none of the conventional-dose treatments have demonstrated a clear superiority over the others and no randomized trials have proved that high-dose chemotherapy is better than conventional treatment. Vinorelbine is a semi-synthetic vinca alkaloid with an in vitro and in vivo experimentally proven broad spectrum of activity, including against malignant brain glioma. We report our experience with a 19-year-old girl with glioblastoma multiforme (GBM) of the deep temporal region recurring 6 months after completing an intensive treatment that included preradiation chemotherapy (chemotherapy as a preradiation "sandwich" phase) with a myeloablative course of thiotepa, tumor bed radiotherapy and postradiation maintenance chemotherapy. The GBM proved fully responsive to intravenous vinorelbine, with a subsequent progression-free interval lasting more than 24 months. This case report suggests that vinorelbine is effective against high-grade pediatric glioma and, since this evidence has only one precedent in the literature (and given the generally poor prognosis for this tumor), even this single success seems worth reporting.

Successful chemotherapy for congenital malignant gliomas: a report of two cases

We describe the cases of 2 patients with a congenital malignant glioma that responded to chemotherapy. In the first case, a 2-month-old boy had a conjugate deviation to the right side and nystagmus. A T(1)-weighted gadolinium-enhanced magnetic resonance image showed a large tumor in his right frontal lobe. The tumor was partially resected, and the histological diagnosis was malignant ganglioglioma. The child then underwent 6 cycles of chemotherapy (mainly carboplatin and etoposide), and the residual tumor shrank. The tumor was then partially resected during a second operation, after which the patient underwent 5 cycles of chemotherapy (a combination of carboplatin, etoposide, vincristine, ifosfamide, cisplatin and cyclophosphamide). The tumor has not recurred in more than 8.5 years. In the second case, a 2-month-old boy had bulging of the anterior fontanel. The T(1)-weighted gadolinium-enhanced magnetic resonance image showed a large suprasellar tumor. The tumor was partially resected, and the histological diagnosis was anaplastic astrocytoma. The patient underwent 8 cycles of chemotherapy (MCNU, carboplatin and etoposide) and the tumor has not recurred in more than 7.5 years. Our experience indicates that, if surgical removal and chemotherapy are done aggressively for malignant gliomas in neonates and infants, long-term survival is possible.

Supratentorial primitive neuroectodermal tumors (S-PNET) in children: A prospective experience with adjuvant intensive chemotherapy and hyperfractionated accelerated radiotherapy

PURPOSE

Supratentorial primitive neuroectodermal tumors (S-PNET) are rare and have a grim prognosis, frequently taking an aggressive course with local relapse and metastatic spread. We report the results of a mono-institutional therapeutic trial.

METHODS AND MATERIALS

We enrolled 15 consecutive patients to preradiation chemotherapy (CT) consisting of high-dose methotrexate, high-dose etoposide, high-dose cyclophosphamide, and high-dose carboplatin, craniospinal irradiation (CSI) with hyperfractionated accelerated radiotherapy (HART) plus focal boost, maintenance with vincristine/lomustine or consolidation with high-dose thiotepa followed by autologous stem-cell rescue.

RESULTS

Median age was 9 years; 7 were male, 8 female. Site of disease was pineal in 3, elsewhere in 12. Six patients were had no evidence of disease after surgery (NED). Of those with evidence of disease after surgery (ED), 2 had central nervous system spread. Of the 9 ED patients, 2 had complete response (CR) and 2 partial response (PR) after CT, 4 stable disease, and 1 progressive disease. Of the 7 ED patients before radiotherapy, 1 had CR, 4 PR, and 2 minor response, thus obtaining a 44% CR + PR after CT and 71% after HART. Because of rapid progression in 2 of the first 5 patients, high-dose thiotepa was systematically adopted after HART in the subsequent 10 patients. Six of 15 patients relapsed (4 locally, 1 locally with dissemination, 1 with dissemination) a mean of 6 months after starting CT, 2 developed second tumors; 5 of 6 relapsers died at a median of 13 months. Three-year progression-free survival, event-free survival, and overall survival were 54%, 34%, and 61%, respectively.

CONCLUSION

Hyperfractionated accelerated RT was the main tool in obtaining responses in S-PNET; introducing the myeloablative phase improved the prognosis (3/10 vs. 3/5 relapses), though the outcome remained unsatisfactory despite the adoption of this intensive treatment.