Pediatric supratentorial high-grade gliomas

Racial disparities in pediatric malignant glioma management: current state of affairs in the United States

BACKGROUND

The diagnosis of malignant glioma confers a poor prognosis in the pediatric population. In the adult demographic, racial disparities exist with respect to access to care and survival. Yet to date no efforts have been made to characterize racial disparities in the care of malignant pediatric gliomas. Correspondingly, the aim of this study was to understand if racial disparities exist in the setting of malignant pediatric gliomas.

METHODS

All pediatric malignant gliomas patients with known race status (White, Black, Other) in the US National Cancer Database (NCDB) between the years 2005-2016 were retrospectively reviewed. Demographic, socioeconomic and clinical data were then abstracted and analyzed by comparison and regression techniques.

RESULTS

A total of 1803 pediatric malignant glioma cases were identified, with 48% female and a median age of 8 years old. Brainstem locations were reported in 48% of cases. Socioeconomically, there were statistically significant differences with respect to insurance status, yearly income, household education level and metropolitan residences between the racial groups (all P < 0.01). With respect to treatment, there was statistical difference in the proportion of patients treated with surgical resection (White 43% vs Black 34% vs Other 37%, P = 0.02). There were no differences between race groups for radiation therapy (P = 0.73) or chemotherapy (P = 0.12). The odds of surgical resection were significantly less in the Black group compared to the White group (OR 0.69, P < 0.01), although there was no difference in overall survival between the two groups in those treated with (P = 0.44) or without (P = 0.27) surgical resection. Primary associations of surgical resection in the Black group were brainstem location (P < 0.05) and lower yearly household income quartiles (P < 0.05).

CONCLUSIONS

Racial disparities exist amongst the management of pediatric malignant gliomas, with undefined impact on survival and quality of life. In this perspective, we identified associations between Black patients and access to surgical treatment. Understanding that there are many elements to patient care, including quality of life, should encourage all clinicians and carers to consider racial disparities appropriately when managing malignant pediatric glioma patients.

Concise review of stereotactic irradiation for pediatric glial neoplasms: Current concepts and future directions

Brain tumors, which are among the most common solid tumors in childhood, remain a leading cause of cancer-related mortality in pediatric population. Gliomas, which may be broadly categorized as low grade glioma and high grade glioma, account for the majority of brain tumors in children. Expectant management, surgery, radiation therapy (RT), chemotherapy, targeted therapy or combinations of these modalities may be used for management of pediatric gliomas. Several patient, tumor and treatment-related characteristics including age, lesion size, grade, location, phenotypic and genotypic features, symptomatology, predicted outcomes and toxicity profile of available therapeutic options should be considered in decision making for optimal treatment. Management of pediatric gliomas poses a formidable challenge to the physicians due to concerns about treatment induced toxicity. Adverse effects of therapy may include neurological deficits, hemiparesis, dysphagia, ataxia, spasticity, endocrine sequelae, neurocognitive and communication impairment, deterioration in quality of life, adverse socioeconomic consequences, and secondary cancers. Nevertheless, improved understanding of molecular pathology and technological advancements may pave the way for progress in management of pediatric glial neoplasms. Multidisciplinary management with close collaboration of disciplines including pediatric oncology, surgery, and radiation oncology is warranted to achieve optimal therapeutic outcomes. In the context of RT, stereotactic irradiation is a viable treatment modality for several central nervous system disorders and brain tumors. Considering the importance of minimizing adverse effects of irradiation, radiosurgery has attracted great attention for clinical applications in both adults and children. Radiosurgical applications offer great potential for improving the toxicity profile of radiation delivery by focused and precise targeting of well-defined tumors under stereotactic immobilization and image guidance. Herein, we provide a concise review of stereotactic irradiation for pediatric glial neoplasms in light of the literature.

Multicentric glioblastoma in a 4-year-old female patient: A case report

In the USA and Germany, pediatric glioblastoma (pGBM) makes up <3% of childhood brain tumors. Occasionally, GBM has multiple contrast lesions and is referred to as multicentric GBM. The current study present a case of a four-year-old female patient presented with headache, vomiting and consciousness disturbance. Radiologically, a neoplastic lesion of the right frontal lobe with hemorrhage, and bilateral thalamus, right temporal and left occipital neoplastic lesions were identified. The right frontal lesion was not continuous to other lesions. It was concluded that the tumor was a multicentric GBM with intra-tumoral hemorrhage. The tumor was pathologically GBM. Following surgery, the patient underwent chemotherapy and radiotherapy, but 11 months after surgery, the patient passed away. This case had features of childhood GBM and multicentric GBM and was difficult to treat.

High-grade gliomas in children and adolescents: is there a role for reoperation?

OBJECTIVE

Tumors of the CNS are the main causes of childhood cancer and have an incidence that exceeds that of leukemia. In addition, they are the leading causes of cancer-related death in childhood. High-grade gliomas account for 11% of such neoplasms and are characterized by aggressive clinical behavior and high morbidity and mortality. There is a lack of studies focusing on the factors that can prolong survival in these patients or guide therapeutic interventions. The authors aimed to investigate the factors related to longer survival durations, with a focus on reoperation for gross-total resection (GTR).

METHODS

In this retrospective cohort study, the authors analyzed 78 patients diagnosed with high-grade gliomas occurring across all CNS locations except diffuse intrinsic pontine gliomas. Patients 0 to < 19 years of age were followed up at the Pediatric Oncology Institute. Overall survival (OS) and progression-free survival (PFS) were analyzed in the context of various prognostic factors, such as age, sex, histology, extent of tumor resection, reoperation for GTR, adjuvant treatment, and treatment initiation from 2010 onward.

RESULTS

With a mean age at diagnosis of 8.7 years, 50% of the patients were female and approximately 39% underwent GTR at some point, which was already achieved in approximately 46% of them in the first surgery. The median OS was 17 months, and PFS was 10 months. In terms of median OS, the authors found no significant difference between those with reoperation for GTR and patients without GTR during treatment. Significant differences were observed in the OS in terms of the extent of resection in the first surgery, age, sex, Ki-67 expression, adjuvant treatment, and treatment initiation from 2010 onward. Furthermore, the PFS values significantly differed between those with GTR in the first surgery and Ki-67 expression ≥ 50%.

CONCLUSIONS

This study demonstrates the importance of GTR for these neoplasms, highlights the role of surgeons in its achievement in the first attempt, and questions the role of reoperation for this purpose. Finally, this study further supports the use of combined adjuvant treatment for the improvement of OS and PFS.

Persistent STAG2 mutation despite multimodal therapy in recurrent pediatric glioblastoma

Similar to their adult counterparts, the prognosis for pediatric patients with high-grade gliomas remains poor. At time of recurrence, treatment options are limited and remain without consensus. This report describes the genetic findings, obtained from whole-exome sequencing of a pediatric patient with glioblastoma who underwent multiple surgical resections and treatment with standard chemoradiation, as well as a novel recombinant poliovirus vaccine therapy. Strikingly, despite the variety of treatments, there was persistence of a tumor clone, characterized by a deleterious STAG2 mutation, whose deficiency in preclinical studies can cause aneuploidy and aberrant mitotic progression, but remains understudied in the clinical setting. There was near elimination of an EGFR mutated and amplified tumor clone after gross total resection, standard chemoradiation, and poliovirus therapy, followed by the emergence of a persistently STAG2 mutated clone, with rare mutations in PTPN11 and BRAF, the latter composed of a novel deleterious mutation previously not reported in pediatric glioblastoma (p.D594G). This was accompanied by a mutation signature shift towards one characterized by increased DNA damage repair defects, consistent with the known underlying STAG2 deficiency. As such, this case represents a novel report following the clinical and genetic progression of a STAG2 mutated glioblastoma, including treatment with a novel and emerging immunotherapy. Although STAG2 deficiency comprises only a small subset of gliomas, this case adds clinical evidence to existing preclinical data supporting a role for STAG2 mutations in gliomagenesis and resistance to standard therapies.

Patient and treatment factors associated with survival among pediatric glioblastoma patients: A Surveillance, Epidemiology, and End Results study

Glioblastoma (GBM) is a rare malignancy in children. The United States Surveillance, Epidemiology, and End Results (SEER) database allows large-scale analyses of clinical characteristics and prognostic features. We used it to study patients aged <20 years with histologically confirmed GBM (2000-2010) and examined the relationship between patient demographics, tumor characteristics, patterns of treatment, and outcomes. The primary outcome was disease-specific survival. 302 subjects were identified, with median age 11 years. Median follow-up was 32 months (95% CI 27-39). 34.4% had gross total resection (GTR). 61% underwent radiation after surgery (17% of subjects <3 years, 67% of those aged 4-19 years). Median survival and 2-year survival rates were 20 months and 46.9%, respectively. In multivariate analyses, age, tumor location, extent of resection, and year of diagnosis were significantly associated with the primary outcome. Compared to those aged 0-4 years, subjects aged 5-9 years and 10-14 years had higher risk of mortality. Infratentorial tumor location (HR 2.0, 95% CI 1.2-3.3, p = 0.007) and subtotal resection (HR 2.04, 95% CI 1.4-3.0, p < 0.001) were associated with increased mortality. Later year of diagnosis was significantly associated with decreased risk of death (HR 0.93, 95% CI 0.9-0.99, p = 0.031). There was no association between sex, race, region, or tumor size and the primary outcome. Repeat analyses examining all-cause mortality identified the same risk factors as for CNS cancer-specific mortality. Younger age, supratentorial location, GTR, and later year of diagnosis were associated with improved survival.

Novel GOPC(FIG)-ROS1 fusion in a pediatric high-grade glioma survivor

Pediatric high-grade glioma is a rare tumor characterized by high mortality. The authors report the first case of a high-grade glioma associated with a GOPC(FIG)-ROS1 fusion in a pediatric patient. The patient underwent gross-total resection at the age of 4 years, followed by adjuvant high-dose chemotherapy and autologous hematopoietic stem cell rescue. At 30 months after transplantation, she remains disease free.

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.

LAPTM4B-35 is a novel prognostic factor for glioblastoma

Lysosome-associated protein transmembrane-4 beta (LAPTM4B)-35, a newly identified cancer-associated gene, is overexpressed in a wide variety of malignant tumors. However, studies of its expression and role in glioma have not yet been reported. This study aimed to investigate the expression and the role of LAPTM4B-35 in glioma and to assess its value as a prognostic factor. Seventy-seven glioma cases (Grade II in 18 patients, Grade III in 16 and Grade IV in 43) were immunohistochemically examined for LAPTM4B-35, pAkt, factor VIII and Ki-67 expressions. The LAPTM4B-35 expression score of Grade II gliomas was lower than those of Grade III-IV gliomas (p < 0.05), while the difference between Grade III and IV gliomas was not statistically significant. Of the 43 patients with glioblastoma (GBM), 27 (62.8%) had high LAPTM4B-35 expression, which was associated with high tumor micro-vessel density and pAkt activation. The median progression-free survival (PFS) of GBM patients with high LAPTM4B-35 expression was 5.13 months, significantly shorter than that of those with low LAPTM4B-35 expression (12.0 months, p < 0.0001). The median overall survival (OS) of GBM patients with high LAPTM4B-35 expression was 12.5 months, again significantly shorter than that of those with low LAPTM4B-35 expression (29.6 months, p < 0.0001). Multivariate analysis indicated LAPTM4B-35 to be an independent prognostic factor for PFS and OS of GBM patients. Our findings show LAPTM4B-35 to be strongly associated with tumor proliferation, tumor angiogenesis and poor outcomes of GBM patients, suggesting LAPTM4B-35 to potentially be applicable as a novel prognostic marker and even to possibly play a role in improving GBM treatment.

Malignant Glioma with Neuronal Marker Expression : A Clinicopathological Study of 18 Cases

Objective

Malignant gliomas with neuronal marker expression (MGwNM) are rare and poorly characterized. Increasingly diverse types of MGwNM have been described and these reported cases underscore the dilemmas in the classification and diagnosis of those tumors. The aim of this study is to provide additional insights into MGwNM and present the clinicopathological features of 18 patients.

Methods

We reviewed the medical records of 18 patients diagnosed as MGwNM at our institute between January 2006 and December 2012. Macroscopic total resection was performed in 11 patients (61%). We evaluated the methylation status of O⁶-methylguanine-DNA methyltransferase (MGMT) and expression of isocitrate dehydrogenase 1 (IDH-1) in all cases, and deletions of 1p and 19q in available cases.

Results

The estimated median overall survival was 21.2 months. The median progression-free survival was 6.3 months. Six patients (33%) had MGMT methylation but IDH1 mutation was found in only one patient (6%). Gene analysis for 1p19q performed in nine patients revealed no deletion in six, 19q deletion only in two, and 1p deletion only in one. The extent of resection was significantly correlated with progression free survival on both univariate analysis and multivariate analysis (p=0.002 and p=0.013, respectively).

Conclusion

In this study, the overall survival of MGwNM was not superior to glioblastoma. The extent of resection has a significant prognostic impact on progression-free survival. Further studies of the prognostic factors related to chemo-radio therapy, similar to studies with glioblastoma, are mandatory to improve survival.

Assessing the accuracy of death records and pre-mortem clinical diagnoses in children diagnosed with brain tumors: A retrospective chart review of children in British Columbia, Canada

The advantages of autopsy have been demonstrated in pediatric oncology; however, it is unknown to what extent the utility of autopsy is in deceased children diagnosed with a pediatric brain tumor (PBT). The purpose of this study was to describe the frequency of autopsy, prevalence of clinical discrepancies, and accuracy of cancer registry death records for deceased children diagnosed with a PBT in British Columbia, Canada. A retrospective chart review was performed of medical records and autopsy reports of pediatric patients diagnosed with a PBT that died between 1982 and 2012 in British Columbia. Clinical discrepancies between pre- and post-mortem findings were classified based on a modified classification system of the Goldman Criteria. The overall autopsy rate was 15.5% (32 of 206) during 1982-2012, with a significant (P=0.001) decrease of 22.4% observed between decade 1 (32.8%) and decade 2 (10.4%) and a further slight decrease (4.5%) between decade 2 (10.4%) and decade 3 (5.9%) (P=0.379). A third of patients had discrepancies between pre-mortem and post-mortem clinical diagnoses, with slightly over 10% of these cases revealing information that would have altered the probability of survival had it been known prior to death. More than half (59.3%) of cases had discordant cause of death as recorded in the cancer registry when compared to autopsy findings. Autopsy for children diagnosed with a PBT can provide health care professionals with important information about the accuracy of their diagnoses and evaluate the efficacy of therapy.

Brain Tumor Immunotherapy: What have We Learned so Far?

High grade glioma is a rare brain cancer, incurable in spite of modern neurosurgery, radiotherapy, and chemotherapy. Novel approaches are in research, and immunotherapy emerges as a promising strategy. Clinical experiences with active specific immunotherapy demonstrate feasibility, safety and most importantly, but incompletely understood, prolonged long-term survival in a fraction of the patients. In relapsed patients, we developed an immunotherapy schedule and we categorized patients into clinically defined risk profiles. We learned how to combine immunotherapy with standard multimodal treatment strategies for newly diagnosed glioblastoma multiforme patients. The developmental program allows further improvements related to newest scientific insights. Finally, we developed a mode of care within academic centers to organize cell-based therapies for experimental clinical trials in a large number of patients.

Altered global histone-trimethylation code and H3F3A-ATRX mutation in pediatric GBM

Mutations in H3.3-ATRX-DAXX chromatin remodeling pathway have been reported in pediatric GBMs. H3.3 (H3F3A) mutations may affect transcriptional regulation by altered global histone-methylation. Therefore, we analyzed yet partly understood global histone code (H3K-4/9/27/36) trimethylation pattern in H3F3A-ATRX mutants and wild-type. H3F3A, HIST1H3B, IDH1, ATRX, DAXX and Tp53 mutations were identified by sequencing/immunohistochemistry in 27 pediatric GBMs. Global histone-methylation H3K-4/9/27/36me3 and Polycomb-protein EZH2 expression were evaluated by immunohistochemistry. H3F3A-ATRX mutation was observed in 66.7 % (18/27) of pediatric GBMs. K27M and G34R-H3F3A mutations were found in 37 % (10/27) and 14.8 % (4/27) patients respectively. G34V-H3F3A, HIST1H3B and IDH1 mutations were absent. Notably, commonest global histone-methylation mark lost was H3K27me3 (17/25, 68 %) followed by H3K4me3 (45.5 %, 10/22) and H3K9me3 (18.2 %, 4/22). Global H3K36me3 showed no loss. Most significant observation was loss of one or more histone-trimethylation mark in 80 % (20/25) pediatric GBMs. Notably, simultaneous loss of H3K27me3 and H3K4me3 were present in 7/22 (31.8 %) of pediatric GBMs. Low expression of EZH2 was found in 12/24 (50 %) of cases. However no significant correlation of loss of histone-marks or EZH2 expression with H3F3A-ATRX mutants (loss of at least one histone-marks in 87.5 % (14/16) cases) versus wild-types (loss of at least one histone-marks in 75 % (6/8) cases) was seen. The present study highlights for the first time combinatorial loss of one or more histone-trimethylation marks associated with majority of pediatric GBMs and the finding suggests significant role of histone-code in the molecular biology that underlies pediatric GBMs. Hence therapies for patients with particular combinations of histone modifications present opportunity to design innovative patient-tailored treatment protocols.

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.

Dendritic cell vaccination for glioblastoma multiforme: review with focus on predictive factors for treatment response

Glioblastoma multiforme (GBM) is the most common and most aggressive type of primary brain cancer. Since median overall survival with multimodal standard therapy is only 15 months, there is a clear need for additional effective and long-lasting treatments. Dendritic cell (DC) vaccination is an experimental immunotherapy being tested in several Phase I and Phase II clinical trials. In these trials, safety and feasibility have been proven, and promising clinical results have been reported. On the other hand, it is becoming clear that not every GBM patient will benefit from this highly personalized treatment. Defining the subgroup of patients likely to respond to DC vaccination will position this option correctly amongst other new GBM treatment modalities, and pave the way to incorporation in standard therapy. This review provides an overview of GBM treatment options and focuses on the currently known prognostic and predictive factors for response to DC vaccination. In this way, it will provide the clinician with the theoretical background to refer patients who might benefit from this treatment.

In vitro drug response and efflux transporters associated with drug resistance in pediatric high grade glioma and diffuse intrinsic pontine glioma

Pediatric high-grade gliomas (pHGG), including diffuse intrinsic pontine gliomas (DIPG), are the leading cause of cancer-related death in children. While it is clear that surgery (if possible), and radiotherapy are beneficial for treatment, the role of chemotherapy for these tumors is still unclear. Therefore, we performed an in vitro drug screen on primary glioma cells, including three DIPG cultures, to determine drug sensitivity of these tumours, without the possible confounding effect of insufficient drug delivery. This screen revealed a high in vitro cytotoxicity for melphalan, doxorubicine, mitoxantrone, and BCNU, and for the novel, targeted agents vandetanib and bortezomib in pHGG and DIPG cells. We subsequently determined the expression of the drug efflux transporters P-gp, BCRP1, and MRP1 in glioma cultures and their corresponding tumor tissues. Results indicate the presence of P-gp, MRP1 and BCRP1 in the tumor vasculature, and expression of MRP1 in the glioma cells themselves. Our results show that pediatric glioma and DIPG tumors per se are not resistant to chemotherapy. Treatment failure observed in clinical trials, may rather be contributed to the presence of drug efflux transporters that constitute a first line of drug resistance located at the blood-brain barrier or other resistance mechanism. As such, we suggest that alternative ways of drug delivery may offer new possibilities for the treatment of pediatric high-grade glioma patients, and DIPG in particular.

Gross total resection correlates with long-term survival in pediatric patients with glioblastoma

OBJECTIVE

Glioblastoma is a rare central nervous system neoplasm in pediatric patients. Few studies focused exclusively on this disease in this population. Available literature suggests that this disease behaves differently between pediatric and adult patients. We set out to study patients younger than 18 years of age, carrying the diagnosis of glioblastoma not of the brainstem, their clinical characteristics and clinical factors associated with clinical outcome.

METHODS

Thirty-seven pediatric patients with the diagnosis of glioblastoma not of the brainstem, who were treated in our institution from 1982-2011, were identified and studied retrospectively.

RESULTS

All patients underwent surgical intervention. Seventeen patients (45.9%) had gross total resection (GTR). Thirteen patients (35.1%) had subtotal resection and seven (18.9%) had biopsy. After surgery, 35 patients received radiation therapy (94.6%) and 34 patients (91.9%) received chemotherapy (various agents depending on the institutional protocols established at the time of treatment and family choice). Median follow-up time was 17.5 months, ranging from 0.5-186 months. The median overall survival is 18.7 months (95% confidence interval 15.7-21.8 months). The survival rate at 1, 2, and 5 years is 63.9%, 44.5%, and 17.6%, respectively. The median overall survival for patients with GTR is 45.1 months (95% confidence interval 27.5-62.8 months), 8.7 or 11.5 months for patients with subtotal resection or biopsy, respectively. GTR was accomplished only in patients with superficially located tumors.

CONCLUSIONS

GTR significantly associates with long-term survival in our population of pediatric patients with glioblastoma not of the brainstem.

Prognosis of pediatric high-grade gliomas with temozolomide treatment: a retrospective, multicenter study

PURPOSE

We analyzed the usefulness of initial or recurrent treatment of temozolomide (TMZ) in pediatric high-grade gliomas (HGGs).

METHODS

Between 2002 and 2010, we performed surgery on 35 patients with 17 glioblastomas, 14 anaplastic astrocytomas, 3 anaplastic oligodendrogliomas, and 1 anaplastic oligoastrocytoma. The male-to-female ratio was 21:14, and the median age was 13 years (range, 3-18 years). The mean follow-up period was 15.9 (± 1.8) months. As the TMZ treatment, 22 patients received the initial treatment and 13 patients at recurrence. We analyzed the prognostic significance of TMZ treatment, tumor location, extent of removal, pathology, and recurrence pattern.

RESULTS

The median progression-free survival (PFS) and overall survival (OS) were 9.7 (± 1.4) and 17.8 (± 2.5) months, respectively. Based on univariate analysis, the median PFS was 9.9 (± 1.6) months in the tumors located in the cerebral hemisphere and 5.6 (± 1.3) months in the diencephalon (p = 0.03). Median PFS was 12.5 (± 1.7) months in the initial treatment and 6.8 (±0.8) months in the recurrent treatment (p = 0.03). The median OS was 14.9 (± 2.3) months in glioblastomas and 24.4 (± 4.1) months in tumors with an anaplastic pathology (p = 0.01). The median OS was 12.1 (± 3.7) months in patients with cerebrospinal fluid (CSF) dissemination and 18.2 (± 2.9) months in patients without CSF dissemination (p = 0.02). Grades 3 and 4 treatment-related toxicity occurred in 7.7-9 % of the patients.

CONCLUSIONS

Initial or recurrent TMZ treatment in pediatric HGGs was safe and tolerable. Initial treatment showed improved PFS compared to recurrent treatment, and both showed similar OS.

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.

Novel survivin inhibitor YM155 elicits cytotoxicity in glioblastoma cell lines with normal or deficiency DNA-dependent protein kinase activity

BACKGROUND

Pediatric glioblastoma is a malignant disease with an extremely poor clinical outcome. Patients usually suffer from resistance to radiation therapy, so targeted drug treatment may be a new possibility for glioblastoma therapy. Survivin is also overexpressed in glioblastoma. YM155, a novel small-molecule survivin inhibitor, has not been examined for its use in glioblastoma therapy.

METHODS

The human glioblastoma cell line M059K, which expresses normal DNA-dependent protein kinase (DNA-PK) activity and is radiation-resistant, and M059J, which is deficient in DNA-PK activity and radiation-sensitive, were used in the study. Cell viability, DNA fragmentation, and the expression of survivin and securin following YM155 treatment were examined using MTT (methylthiazolyldiphenyl-tetrazolium) assay, ELISA assay, and Western blot analysis, respectively.

RESULTS

YM155 caused a concentration-dependent cytotoxic effect, inhibiting the cell viability of both M059K and M059J cells by 70% after 48 hours of treatment with 50 nM YM155. The half-maximal inhibitory concentration (IC50) was around 30-35 nM for both cell lines. Apoptosis was determined to have occurred in both cell lines because immunoreactive signals from the DNA fragments in the cytoplasm were increased 24 hours after treatment with 30 nM YM155. The expression of survivin and securin in the M059K cells was greater than that measured in the M059J cells. Treatment with 30 nM YM155, for both 24 and 48 hours, significantly suppressed the expression of survivin and securin in both cell lines.

CONCLUSION

The novel survivin inhibitor YM155 elicits potent cytotoxicity in glioblastoma cells in vitro via DNA-PK-independent mechanisms. YM155 could be used as a new therapeutic agent for the treatment of human glioblastomas.

Possible differentiation of cerebral glioblastoma into pleomorphic xanthoastrocytoma: an unusual case in an infant

The authors describe an infant girl who, at 10 months of age, presented with a large right parietooccipital tumor causing increased intracranial pressure, mass effect, and midline shift. The tumor was completely resected, and the entirety of the histology was consistent with glioblastoma. She was subsequently placed on adjuvant high-dose chemotherapy consisting of carboplatin, vincristine, and temozolomide, according to Head Start III, Regimen C. Three months after the complete resection, tumor recurrence was noted on MR imaging, during the third cycle of chemotherapy, and biopsy revealed malignant astrocytoma. Given the recurrence and the patient's intolerance to chemotherapy, a palliative course was pursued. Unexpectedly, the patient was alive and had made significant developmental improvements 18 months into palliation. Subsequently, however, signs of increased intracranial pressure developed and imaging demonstrated a very large new tumor growth at the site of prior resection. The recurrence was again fully resected, but microscopy surprisingly revealed pleomorphic xanthoastrocytoma throughout. The clinicopathological and genetic features of this girl's unusual neoplasm are detailed and potential pathogenic hypotheses are explored in this report.

Concomitant intraventricular colloid cyst and low-grade astrocytoma of the brainstem in a 16-year-old boy

Multiple primary brain tumors are commonly observed in patients with a history of brain radiation therapy or neurofibromatosis. The concomitant presence of 2 different types of brain tumors in a single location or chamber is a very rare clinical presentation in the absence of such a predisposing factor. The authors report on the case of a 16-year-old boy presenting with different types of brain tumors in 2 ventricular chambers concomitantly. This boy had a medium-sized colloid cyst of the third ventricle and a large fibrillary astrocytoma fungating from the brainstem into the floor of the fourth ventricle. The lesions were successfully excised in 2 separate surgeries. Radiotherapy was used as the adjuvant mode of therapy. There has been no sign of tumor recurrence after 16 months of follow-up. Clinical awareness and recognition of such a combination of tumors is important because they will dictate special treatment strategies depending on the individual biological aggressiveness of each tumor.

Glioblastoma multiforme with very rapid growth and long-term survival in children: report of two cases and review of the literature

Glioblastoma occurs rarely in pediatric patients (0.6-7.9% of all glioblastomas). Symptom duration is about 3-5 months prior to diagnosis with a dismal prognosis (median survival of 50 weeks). The authors describe two pediatric age patients with histopathologically confirmed glioblastoma multiforme whose lesions appeared within just 1 week of normal computed tomography scan and magnetic resonance imaging. Both patients had long-term survival (one of them 6 years and the other 3 years and 7 months) following tumor resection. The present report serially illustrates the very rapid development of glioblastoma in childhood and emphasizes the importance of serial neuroimaging as well as paying attention to sudden onset headaches in pediatric patients with inconclusive imaging findings.

Integration of autologous dendritic cell-based immunotherapy in the primary treatment for patients with newly diagnosed glioblastoma multiforme: a pilot study

Despite resection, radiochemotherapy, and maintenance temozolomide chemotherapy (TMZm), the prognosis of patients with glioblastoma multiforme (GBM) remains poor. We integrated immunotherapy in the primary standard treatment for eight pilot adult patients (median age 50 years) with GBM, to assess clinical and immunological feasibility and toxicity in preparation of a phase I/II protocol HGG-2006. After maximum, safe resection, leukapheresis was performed before radiochemotherapy, and four weekly vaccinations with autologous GBM lysate-loaded monocyte-derived dendritic cells were given after radiochemotherapy. Boost vaccines with lysates were given during TMZm. During the course of vaccination, immunophenotyping showed a relative increase in CD8+CD25+ cells in six of the seven patients, complying with the prerequisites for implementation of immunotherapy in addition to postoperative radiochemotherapy. In five patients, a more than twofold increase in tumor antigen-reacting IFN-gamma-producing T cells on Elispot was seen at the fourth vaccination compared with before vaccination. In three of these five patients this more than twofold increase persisted after three cycles of TMZm. Quality of life during vaccination remained excellent. Progression-free survival at six months was 75%. Median overall survival for all patients was 24 months (range: 13-44 months). The only serious adverse event was an ischemic stroke eight months postoperatively. We conclude that tumor vaccination, fully integrated within the standard primary postoperative treatment for patients with newly diagnosed GBM, is feasible and well tolerated. The survival data were used to power a currently running phase I/II trial.

Collision tumor of meningioma and malignant astrocytoma

The authors report a 12-year-old boy who was presented with headache, nausea, vomiting and seizure. His magnetic resonance imaging showed 2 adjacent tumors in the region of the left ventricular trigone. The pathology of tumors reported collision tumors composed of meningioma and malignant astrocytoma.

Dendritic cell therapy of high-grade gliomas

The prognosis of patients with malignant glioma is poor in spite of multimodal treatment approaches consisting of neurosurgery, radiochemotherapy and maintenance chemotherapy. Among innovative treatment strategies like targeted therapy, antiangiogenesis and gene therapy approaches, immunotherapy emerges as a meaningful and feasible treatment approach for inducing long-term survival in at least a subpopulation of these patients. Setting up immunotherapy for an inherent immunosuppressive tumor located in an immune-privileged environment requires integration of a lot of scientific input and knowledge of both tumor immunology and neuro-oncology. The field of immunotherapy is moving into the direction of active specific immunotherapy using autologous dendritic cells (DCs) as vehicle for immunization. In the translational research program of the authors, the whole cascade from bench to bed to bench of active specific immunotherapy for malignant glioma is covered, including proof of principle experiments to demonstrate immunogenicity of patient-derived mature DCs loaded with autologous tumor lysate, preclinical in vivo experiments in a murine orthotopic glioma model, early phase I/II clinical trials for relapsing patients, a phase II trial for patients with newly diagnosed glioblastoma (GBM) for whom immunotherapy is integrated in the current multimodal treatment, and laboratory analyses of patient samples. The strategies and results of this program are discussed in the light of the internationally available scientific literature in this fast-moving field of basic science and translational clinical research.

Diagnosis of childhood astrocytomas

BACKGROUND

Astrocytomas are the most common brain tumours, accounting for 28 - 50% of all primary CNS tumours. Diagnosis of CNS tumours remains difficult because the varied and nonspecific presentations of CNS tumours in childhood. Objectives/method: The clinical presentations of CNS astrocytomas vary with their sites of location; therefore, a period of uncertainty often precedes diagnosis, and approximately 42% of patients with an intracranial process make several visits to various physicians between the onset and diagnosis. However, on clinical suspicion of a brain tumour, a wide range of neuroimaging techniques may be used to assess the diagnosis of paediatric brain lesions. In this review the authors, for ease of presentation, describe the clinical presentations of supratentorial, infratentorial and spinal cord astrocytomas as well as their radiological and pathological features, and discuss their differential diagnoses.

RESULTS/CONCLUSIONS

Understanding and mastering the numerous imaging features of several subtypes of primary brain tumours affecting children, in addition to radiological features of non-tumoural disorders, remains a significant challenge and demands increased awareness of the paediatric brain diseases.

Initial management of childhood brain tumors: neurosurgical considerations

Intracranial tumors are the most common solid tumors in children. The infratentorial compartment will be the primary site for 60% to 70% of these tumors, including astrocytomas, medulloblastomas, and ependymomas. Several technological advancements have increased our knowledge of the cell biology of pediatric brain tumors, facilitated earlier diagnosis, and improved neurosurgical resections while minimizing neurological deficits. These in turn have not only improved the survival of children with brain tumors but also their quality of life. Current management strategies in most cases rely on surgery coupled with adjuvant therapies, including radiation therapy and chemotherapy. The vulnerability of the immature brain to adjuvant therapies creates many challenges for the treating physician. We review current diagnostic and therapeutic approaches and outcome for children harboring the most common pediatric brain tumors: astrocytomas (low-grade and high-grade glioma), ependymoma, medulloblastoma, and craniopharyngioma. The emphasis will be on the neurosurgical management of children with these tumors.

Down-regulation of RNA editing in pediatric astrocytomas: ADAR2 editing activity inhibits cell migration and proliferation

Since alterations in post-transcriptional events can contribute to the appearance and/or progression of cancer, we investigated whether RNA editing, catalyzed by the ADAR (adenosine deaminases that act on RNA) enzymes, is altered in pediatric astrocytomas. We find a decrease in ADAR2 editing activity that seems to correlate with the grade of malignancy in children. Despite the loss of ADAR2 editing activity in tumor tissues, the high grade astrocytomas do not exhibit alterations in ADAR2 expression when compared with their specific control tissues. However, high expression levels of ADAR1 and ADAR3 were found in tumors when compared with normal tissues dissected in the same area of the brain. We reintroduced either ADAR2 or the inactive version of ADAR2 in three astrocytoma cell lines (U118, A172, U87). The "reverted" editing status is necessary and sufficient for a significant decrease in cell malignant behavior as measured by proliferation, cell cycle, and migration assays. We show that elevated levels of ADAR1, as found in astrocytomas, do indeed interfere with ADAR2 specific editing activity. Furthermore, we show that the endogenous ADAR1 can form heterodimers with ADAR2 in astrocytes.

Congenital glioblastoma: a clinicopathologic and genetic analysis

Congenital central nervous system (CNS) tumors are uncommon, accounting for 1% of all childhood brain tumors. They present clinically either at birth or within the first 3 months. Glioblastoma (GBM) only rarely occurs congenitally and has not been fully characterized. We examined clinicopathologic features and genetic alterations of six congenital GBMs. Tumors were seen by neuroimaging as large, complex cerebral hemispheric masses. All showed classic GBM histopathology, including diffuse infiltration, dense cellularity, GFAP-positivity, high mitotic activity, endothelial proliferation and pseudopalisading necrosis. Neurosurgical procedures and adjuvant therapies varied. Survivals ranged from 4 days to 7.5 years; two of the three long-term survivors received chemotherapy, whereas the three short-term survivors did not. Paraffin-embedded tissue sections were used for FISH analysis of EGFR, chromosomes 9p21 (p16/CDKN2A) and 10q ( PTEN/DMBT1); sequencing of PTEN and TP53; and immunohistochemistry for EGFR and p53. We uncovered 10q deletions in two cases. No EGFR amplifications, 9p21 deletions, or mutations of TP53 or PTEN were noted; however, nuclear p53 immunoreactivity was strong in 5/6 cases. Tumors were either minimally immunoreactive (n = 3) or negative (n = 3) for EGFR. We conclude that congenital GBMs show highly variable survivals. They are genetically distinct from their adult counterparts and show a low frequency of known genetic alterations. Nonetheless, the strong nuclear expression of p53 in these and other pediatric GBMs could indicate that p53 dysregulation is important to tumorigenesis.

MGMT promoter methylation correlates with survival benefit and sensitivity to temozolomide in pediatric glioblastoma

BACKGROUND

Methylation of the DNA-repair gene O6-methylguanine-DNA methyltransferase (MGMT) causes gene silencing. This epigenetic modification has been associated with a favorable prognosis in adult patients with glioblastoma (GBM) who receive temozolomide and other alkylating agents. We explored MGMT promoter methylation in pediatric GBM and its relationship to survival and temozolomide sensitivity.

PROCEDURE

We performed a retrospective study of MGMT promoter methylation in 10 pediatric GBM. The methylation status of the MGMT was determined using a 2-stage methylation specific PCR analysis on DNA extracted from tumor specimens which had been snap frozen at surgery. The relationships between MGMT promoter methylation and patient outcome and response to temozolomide were evaluated.

RESULTS

Four of our 10 pediatric patients with GBM were found to have methylation of the MGMT gene promoter. Methylation of the MGMT promoter was shown to correlate (P = 0.0005) with survival. The average survival time for patients with methyltated MGMT was 13.7 months as compared to 2.5 months for the 6 patients with unmethylated MGMT promoter. Of the seven patients that received temozolomide, those patients that had the methylated MGMT gene promoter responded better to treatment (P = 0.007).

CONCLUSIONS

As in adults, pediatric GBM patients with methylated MGMT promoter benefited from temozolomide. However, a stronger correlation with overall survival, regardless of treatment, was observed in this group of patients. These data suggest that MGMT methylation may be a prognostic factor for survival in pediatric GBM, as well as a marker for temozolomide sensitivity.

Current concepts in the molecular genetics of pediatric brain tumors: implications for emerging therapies

BACKGROUND

The revolution in molecular biology that has taken place over the past 2 decades has provided researchers with new and powerful tools for detailed study of the molecular mechanisms giving rise to the spectrum of pediatric brain tumors. Application of these tools has greatly advanced our understanding of the molecular pathogenesis of these lesions.

REVIEW

After familiarizing readers with some promising new techniques in the field of oncogenomics, this review will present the current state of knowledge as it pertains to the molecular biology of pediatric brain neoplasms. Along the way, we hope to highlight specific instances where the detailed mechanistic knowledge acquired thus far may be exploited for therapeutic advantage.

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.

Immunotherapy for malignant gliomas: emphasis on strategies of active specific immunotherapy using autologous dendritic cells

REVIEW

In this review, we discuss immunotherapy for malignant gliomas.

EMPHASIS

The emphasis is on the novel strategy of active specific immunotherapy using dendritic cells as antigen-presenting cells, especially its theoretical concepts and advantages, specific requirements, critical issues, pre-clinical and early clinical experience. Dendritic cell vaccination is situated in the diversity of other immunotherapeutical approaches.

FURTHER DISCUSSION

Future directions, challenges, and drawbacks will be discussed.

Surgery and adjuvant dendritic cell-based tumour vaccination for patients with relapsed malignant glioma, a feasibility study

Patients with relapsed malignant glioma have a poor prognosis. We developed a strategy of vaccination using autologous mature dendritic cells loaded with autologous tumour homogenate. In total, 12 patients with a median age of 36 years (range: 11–78) were treated. All had relapsing malignant glioma. After surgery, vaccines were given at weeks 1 and 3, and later every 4 weeks. A median of 5 (range: 2–7) vaccines was given. There were no serious adverse events except in one patient with gross residual tumour prior to vaccination, who repetitively developed vaccine-related peritumoral oedema. Minor toxicities were recorded in four out of 12 patients. In six patients with postoperative residual tumour, vaccination induced one stable disease during 8 weeks, and one partial response. Two of six patients with complete resection are in CCR for 3 years. Tumour vaccination for patients with relapsed malignant glioma is feasible and likely beneficial for patients with minimal residual tumour burden.