Epidemiology of brain tumors

Lifetime occupational exposure to metals and welding fumes, and risk of glioma: a 7-country population-based case-control study

BACKGROUND

Brain tumor etiology is poorly understood. Based on their ability to pass through the blood-brain barrier, it has been hypothesized that exposure to metals may increase the risk of brain cancer. Results from the few epidemiological studies on this issue are limited and inconsistent.

METHODS

We investigated the relationship between glioma risk and occupational exposure to five metals - lead, cadmium, nickel, chromium and iron- as well as to welding fumes, using data from the seven-country INTEROCC study. A total of 1800 incident glioma cases and 5160 controls aged 30-69 years were included in the analysis. Lifetime occupational exposure to the agents was assessed using the INTEROCC JEM, a modified version of the Finnish job exposure matrix FINJEM.

RESULTS

In general, cases had a slightly higher prevalence of exposure to the various metals and welding fumes than did controls, with the prevalence among ever exposed ranging between 1.7 and 2.2% for cadmium to 10.2 and 13.6% for iron among controls and cases, respectively. However, in multivariable logistic regression analyses, there was no association between ever exposure to any of the agents and risk of glioma with odds ratios (95% confidence intervals) ranging from 0.8 (0.7-1.0) for lead to 1.1 (0.7-1.6) for cadmium. Results were consistent across models considering cumulative exposure or duration, as well as in all sensitivity analyses conducted.

CONCLUSIONS

Findings from this large-scale international study provide no evidence for an association between occupational exposure to any of the metals under scrutiny or welding fumes, and risk of glioma.

Adult Glioblastoma

Glioblastoma (GBM) is a rare tumor and one of the most challenging malignancies to treat in all of oncology. Although advances have been made in the treatment of GBM, encouraging outcomes typically are not observed; patients diagnosed with these tumors generally have a dismal prognosis and poor quality of life as the disease progresses. This review summarizes the clinical presentation of GBM, diagnostic methods, evidentiary basis for the current standards of care, and investigational approaches to treat or manage GBM. Because the track record for developing effective therapies for GBM has been dismal, we also review the challenges to successful therapeutic and biomarker development.

Demographics and Incidence of Histologically Confirmed Intracranial Tumors: A Five-year, Two-center Prospective Study

Introduction

Intracranial tumors (ICTs) are a diverse group of malignancies that pose an immediate threat to patients' lives, no matter their local or metastatic origin, benign or malignant nature. These lesions have severe clinical courses and need to be diagnosed and treated as soon as possible, with pathological verification being the pivotal moment in the process of determining curative modalities.

Aim

The aim of this study was to compare the incidence of histologically confirmed ICTs in Eastern Bulgaria, based on their type (primary, metastatic, and non-volume occupying lesions (NVOL)), their respective subtypes, and incidence in a descriptive manner.

Materials and Methods

For a period of five full calendar years (January 1st, 2012 – December 31st, 2016), all histologically confirmed cases of intracranial tumors were prospectively collected from two individual tertiary healthcare institutions. The cases were then statistically analyzed in a descriptive manner, and incidences of primary, metastatic, and NVOL were compared with regards to their specific origins, types, and subtypes. Metastatic tumors were further segregated relative to their intracranial metastatic location.

Results

The total number of individual ICTs registered in the set timeframe was 822. Primary ICTs represented a total of 66.12% of the histologically confirmed cases, with the most common entries being tumors from a glial and meningeal origin, 30.90% were histologically confirmed as metastatic ICTs, from which the most common entries were of pulmonary origin, and the other 2.94% were NVOL. On behalf of their intracranial metastatic location, metastatic tumors were located predominantly in the supratentorial region, represented as a total of 87.80%, while the other 12.20% were located in the subtentorial region. Based on the descriptive analysis, the annual incidence per 100,000 capita of all ICTs is 9.12, comprised of 6.03 per 100,000 for primary ICTs, 2.82 per 100,000 for metastatic ICTs, and 0.27 per 100,000 for NVOL. The annual incidence of the most commonly diagnosed primary ICTs per 100,000 is 2.36 for meningioma, 2.03 for glioblastoma, and 0.48 for pituitary adenoma. The annual incidence of the most commonly diagnosed metastatic ICTs per 100,000 is 1.32 for lung cancer metastases, 0.28 for gastrointestinal tract (GIT) metastases, 0.22 for melanoma, and 0.17 for breast cancer metastases.

Conclusion

Based on our results, primary ICTs are operated and biopsied more than two times as much as metastatic ICTs and only a small fraction of neurosurgical interventions are undertaken due to NVOL. Metastatic ICTs are predominantly supratentorial with no evidence of a tumor predominantly metastasizing in the subtentorial region. The demographics reported in the study establish some aspects of age and gender preferences, as well as the annual incidence per 100,000 for the most commonly diagnosed types of ICTs in our population.

Small-Molecule Kinase-Inhibitors-Loaded Boron Cluster as Hybrid Agents for Glioma-Cell-Targeting Therapy

The reported new anilinoquinazoline-icosahedral borane hybrids have been evaluated as glioma targeting for potential use in cancer therapy. Their anti-glioma activity depends on hybrids' lipophilicity; the most powerful compound against glioma cells, a 1,7-closo-derivative, displayed at least 3.3 times higher activity than the parent drug erlotinib. According to the cytotoxic effects on normal glia cells, the hybrids were selective for epidermal growth factor receptor (EGFR)-overexpressed tumor cells. These boron carriers could be used to enrich glioma cancer cells with boron for cancer therapy.

Epidemiology of Brain Tumors

Brain tumors are the commonest solid tumor in children, leading to significant cancer-related mortality. Several hereditary syndromes associated with brain tumors are nonfamilial. Ionizing radiation is a well-recognized risk factor for brain tumors. Several industrial exposures have been evaluated for a causal association with brain tumor formation but the results are inconclusive. A casual association between the common mutagens of tobacco, alcohol, or dietary factors has not yet been established. There is no clear evidence that the incidence of brain tumors has changed over time. This article presents the descriptive epidemiology of the commonest brain tumors of children and adults.

Expression of Cathepsins B, D, and G in Isocitrate Dehydrogenase-Wildtype Glioblastoma

AIM

To investigate the expression of cathepsins B, D, and G, in relation to the cancer stem cell (CSC) subpopulations, we have previously characterized within isocitrate dehydogenase (IDH)-wildtype glioblastoma (IDHWGB).

METHODS

3,3-Diaminobezidine (DAB) immunohistochemical (IHC) staining for cathepsins B, D, and G, was performed on 4μm-thick formalin-fixed paraffin-embedded IDHWGB samples obtained from six patients. Two representative DHWGB samples from the original cohort of patients were selected for immunofluorescent (IF) IHC staining, to identify the localization of the cathepsins in relation to the CSC subpopulations. NanoString gene expression analysis and colorimetric in situ hybridization (CISH) were conducted to investigate the transcriptional activation of genes encoding for cathepsins B, D, and G. Data obtained from cell counting of DAB IHC-stained slides and from NanoString analysis were subjected to statistical analyses to determine significance.

RESULTS

Cathepsin B and cathepsin D were detected in IDHWGB by DAB IHC staining. IF IHC staining demonstrated the expression of both cathepsin B and cathepsin D by the OCT4⁺ and SALL4⁺ CSC subpopulations. NanoString gene analysis and CISH confirmed the abundant transcript expression of these cathepsins. The transcriptional and translational expressions of cathepsin G were minimal and were confined to cells within the microvasculature.

CONCLUSION

This study demonstrated the expression of cathepsin B and cathepsin D but not cathepsin G within the CSC subpopulations of IDHWGB at both the transcriptional and translational level. Cathepsin G was expressed at low levels and was not localized to the CSC population of IDHWGB. The novel finding of cathepsin B and cathepsin D in IDHWGB suggests the presence of bypass loops for the renin-angiotensin system, which may facilitate the production of angiotensin peptides. Elucidating the precise role of these cathepsins may lead to better understanding and more effective treatment of this aggressive tumor.

MicroRNA-548c-3p inhibits T98G glioma cell proliferation and migration by downregulating c-Myb

MicroRNAs (miRNAs/miRs) are short non-coding RNAs (between 20 and 22 nucleotides) that regulate gene expression by binding to the 3'-untranslated region of target mRNA, and preventing protein translation or inducing mRNA destabilization. miRNAs are predicted to target ~60% of all mRNAs, therefore providing a marked degree of regulation of a number of cellular processes. In the present study, the expression of miR-548c-3p was determined by reverse transcription-quantitative polymerase chain reaction analysis and demonstrated to be markedly downregulated in clinical malignant glioma tissues and the glioma T98G cell line compared with normal human brain tissue. Transfection of miR-548c-3p inhibited cell proliferation by inducing G₁ cell cycle arrest and also inhibited the migration of the T98G cells in vitro. Furthermore, a bioinformatic algorithm and a luciferase reporter assay identified proto-oncogene c-Myb (c-Myb) as a potential direct target of miR-548c-3p. Further experiments demonstrated that the inhibition of c-Myb by miR-548c-3p partially mediated the antitumor effect of miR-548c-3p. The results of the present study provide the novel insight that miR-548c-3p inhibits glioma tumorigenesis by targeting c-Myb. Therefore, miR-548c-3p may contribute to the development of improved glioma treatment.

Imaging characteristics and surgical treatment of invasive meningioma

In order to provide an effective way to prevent or substantially delay the recurrence of invasive meningioma, and improve the curative effect of surgical treatment, we collected and analyzed the clinical manifestations, pathological features, preoperative imaging characteristics as well the data obtained during the surgical treatment of invasive meningioma. From February 2014 to February 2016, 59 patients with invasive meningioma were enrolled in this study. Invasive meningioma was confirmed in all patients by operation. Information about clinical manifestations, pathological features, preoperative imaging and surgical treatment were collected and analyzed. After surgery, pathological specimens were collected, and cases were confirmed as invasive meningioma by pathological examination. The course of disease ranged from 15 days to 7 years (average, 13.2 months). We used World Health Organization (WHO) criteria for classification of meningioma in the nervous system tumors as our reference. Symptoms were as follows: Intracranial hypertension (29 cases), cranial nerve dysfunction (10 cases), epilepsy (11 cases) and other symptoms (9 cases). We had 56 cases of WHO grade I; 6 cases of WHO grade II and 7 cases of WHO grade III. Surgical removal was: Simpson grade I (56 cases), Simpson grade II (2 cases), Simpson grade III and above (56 cases). We used before surgery imaging data to formulate our surgical plan. In general, during surgeries we did not proceed to complete resection, because in the majority of cases, some key structures were invaded and meningioma was very deep and any attempt for total resection could easily lead to significant damage to these structures.

Epidemiology of adult-onset hydrocephalus: institutional experience with 2001 patients

OBJECTIVE Adult-onset hydrocephalus is not commonly discussed in the literature, especially regarding its demographic distribution. In contrast to pediatric hydrocephalus, which is related to a primary CSF pathway defect, its development in adults is often secondary to other pathologies. In this study, the authors investigated the epidemiology of adult-onset hydrocephalus as it pertains to different etiologies and in reference to age, sex, and race distributions. METHODS The authors retrospectively reviewed the clinical notes of 2001 patients with adult-onset hydrocephalus who presented to Louisiana State University Health Sciences Center within a 25-year span. Significant differences between the groups were analyzed by a chi-square test; p < 0.05 was considered significant. RESULTS The overall mean (± SEM) incidence of adult hydrocephalus in this population was 77 ± 30 per year, with a significant increase in incidence in the past decade (55 ± 3 [1990-2003] vs 102 ± 6 [2004-2015]; p < 0.0001). Hydrocephalus in a majority of the patients had a vascular etiology (45.5%) or was a result of a tumor (30.2%). The incidence of hydrocephalus in different age groups varied according to various pathologies. The incidence was significantly higher in males with normal-pressure hydrocephalus (p = 0.03) or head injury (p = 0.01) and higher in females with pseudotumor cerebri (p < 0.0001). In addition, the overall incidence of hydrocephalus was significantly higher in Caucasian patients (p = 0.0002) than in those of any other race. CONCLUSIONS Knowledge of the demographic variations in adult-onset hydrocephalus is helpful in achieving better risk stratification and better managing the disease in patients. For general applicability, these results should be validated in a large-scale meta-analysis based on a national population database.

Cancers of the brain and CNS: global patterns and trends in incidence

Background

Cancers of the brain and CNS constitute a group of rare and heterogeneous tumors. Increasing incidence in Western populations has been linked to improvements in diagnostic technology, although interpretation is hampered by changes in diagnosis and reporting. The present study examines geographic and temporal variations in incidence rates of brain and CNS cancers worldwide.

Methods

Data from successive volumes of Cancer Incidence in Five Continents were used, including 96 registries in 39 countries. We used Joinpoint regression to estimate the average annual percentage change and its 95% CI.

Results

Globally, a large variability in the magnitude of the diagnosis of new cases of brain and CNS cancer was found, with a 5-fold difference between the highest rates (mainly in Europe) and the lowest (mainly in Asia). Increasing rates of brain and CNS cancer were found in South America, namely in Ecuador, Brazil, and Colombia; in eastern Europe (Czech Republic and Russia), in southern Europe (Slovenia), and in the 3 Baltic countries. Trends were similar between sexes, although decreasing trends in men and women were seen in Japan and New Zealand.

Conclusions

Important regional variations in brain and CNS cancers exist, and given an increasing burden and risk worldwide, there is a need for further etiological research that focuses on the elucidation of environmental risk. The trends are sufficiently complex and diffuse, however, to warrant a cautious approach to interpretation.

Fish intake and the risk of brain tumor: a meta-analysis with systematic review

Background

Fish, rich in ω-3 polyunsaturated fatty acids, has been found to be associated with lower risk of several types of cancer risk, and beneficial for brain development. However, the association between fish intake and brain tumor risk is still inconsistent. Therefore, we conducted a meta-analysis to clarify the association.

Methods

Relevant studies were identified from PubMed and EMBASE databases. The pooled relative risks were obtained by the fixed-effects model when no substantial heterogeneity was observed. Otherwise, the random-effects model was employed. Subgroup and publication bias analyses were also performed.

Results

Nine observational studies were included in the meta-analysis. The pooled relative risk of brain cancer for the highest vs. lowest category of fish intake was 0.83 (95% confidence interval [CI]: 0.70–0.99). No significant heterogeneity was detected. Dose-response analysis showed that the RR per 100 g/day increase in fish intake was 0.95 (95% CI: 0.91–0.98). The results remained unchanged in subgroup and sensitivity analyses.

Conclusions

The results of our meta-analysis suggest that fish intake might be associated with lower risk of brain cancer risk. The finding should be further confirmed by future cohort studies with validated questionnaires and strict control of confounders.

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-016-0223-4) contains supplementary material, which is available to authorized users.

Glioblastoma Multiforme: A Review of its Epidemiology and Pathogenesis through Clinical Presentation and Treatment

Glioblastoma multiforme (GBM) is one of the most malignant types of central nervous system tumors. Despite advances in treatment modalities it remains largely incurable. The objective of our review is to provide a holistic picture of GBM epidemiology, etiology, pathogenesis, clinical findings and treatment. A literature search was conducted for GBM at PubMed and Google Scholar, with relevant key words like glioblastoma multiforme, pathogenesis, signs and symptoms, treatment etc., and papers published until 2015 were reviewed. It was found that radiation and certain genetic syndromes are the only risk factors identified to date for GBM. Depending on the tumor site patients may present to the clinic with varying symptoms. To confirm the presence and the extent of tumor, various invasive and non-invasive imaging techniques require employment. The literature survey revealed the pathogenesis to involve aberrations of multiple signaling pathways through multiple genetic mutations and altered gene expression. Although several treatment options are available, including surgery, along with adjuvant chemo- and radio-therapy, the disease has a poor prognosis and patients generally succumb within 14 months of diagnosis.

PPARα Antagonist AA452 Triggers Metabolic Reprogramming and Increases Sensitivity to Radiation Therapy in Human Glioblastoma Primary Cells

Glioblastoma (GB) is the most common cancer in the brain and with an increasing incidence. Despite major advances in the field, there is no curative therapy for GB to date. Many solid tumors, including GB, experienced metabolic reprogramming in order to sustain uncontrolled proliferation, hypoxic conditions, and angiogenesis. PPARs, member of the steroid hormone receptor superfamily, are particularly involved in the control of energetic metabolism, particularly lipid metabolism, which has been reported deregulated in gliomas. PPARα was previously indicated by us as a potential therapeutic target for this neoplasm, due to the malignancy grade dependency of its expression, being particularly abundant in GB. In this work, we used a new PPARα antagonist on patient-derived GB primary cells, with particular focus on the effects on lipid metabolism and response to radiotherapy. The results obtained demonstrated that blocking PPARα results in cell death induction, increase of radiosensitivity, and decrease of migration. Therefore, AA452 is proposed as a new adjuvant for the gold standard therapies for GB, opening the possibility for preclinical and clinical trials for this class of compounds. J. Cell. Physiol. 232: 1458-1466, 2017. © 2016 Wiley Periodicals, Inc.

Targeted brain delivery nanoparticles for malignant gliomas

Brain tumors display the highest mortality rates of all childhood cancers, and over the last decade its prevalence has steadily increased in elderly. To date, effective treatments for brain tumors and particularly for malignant gliomas remain a challenge mainly due to the low permeability and high selectivity of the blood-brain barrier (BBB) to conventional anticancer drugs. In recent years, the elucidation of the cellular mechanisms involved in the transport of substances into the brain has boosted the development of therapeutic-targeted nanoparticles (NPs) with the ability to cross the BBB. Here, we present a comprehensive overview of the available therapeutic strategies developed against malignant gliomas based on 'actively targeted' NPs, the challenges of crossing the BBB and blood-brain tumor barrier as well as its mechanisms and a critical assessment of clinical studies that have used targeted NPs for the treatment of malignant gliomas. Finally, we discuss the potential of actively targeted NP-based strategies in clinical settings, its possible side effects and future directions for therapeutic applications. First draft submitted: 4 October 2016; Accepted for publication: 14 October 2016; Published online: 23 November 2016.

Cyclooxygenase-2 in glioblastoma multiforme

Glioblastoma multiforme (GBM) represents the most prevalent brain primary tumor, yet there is a lack of effective treatment. With current therapies, fewer than 5% of patients with GBM survive more than 5 years after diagnosis. Mounting evidence from epidemiological studies reveals that the regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is correlated with reduced incidence of GBM, suggesting that cyclooxygenase-2 (COX-2) and its major product within the brain, prostaglandin E2 (PGE₂), are involved in the development and progression of GBM. Here, we highlight our current understanding of COX-2 in GBM proliferation, apoptosis, invasion, angiogenesis, and immunosuppression by focusing on recent in vitro and in vivo experimental data. We also discuss the feasibility of COX-2 as a therapeutic target for GBM in light of the latest human studies.

Descriptive epidemiology of brain and central nervous system cancers in Central and South America

RATIONALE AND OBJECTIVE

Although malignant tumors of the brain and central nervous system (CNS) represent less than 3% of new cancer cases estimated worldwide, they cause significant morbidity and in the case of gliomas, the most common histological type, have a poor prognosis. We describe patterns and trends in brain and CNS incidence and mortality in Central and South America.

METHODS

We obtained regional- and national-level incidence data from 48 population-based cancer registries in 13 countries and cancer deaths from the WHO mortality database for 18 countries. We estimated world population age-standardized incidence rates (ASRs) and mortality rates (ASMRs) per 100,000 person-years, and present incidence by histological subtypes.

RESULTS

In general, incidence rates were higher in males than in females. The highest incidence ASRs were observed for Cuba (5.1 males, 3.6 females) in Central America, and for Brazil (6.4 males, 4.8 females) and Uruguay (6.2 and 4.0) in South America. Mortality rates closely followed the pattern of incidence rates. Argentina, Brazil and Chile showed increasing mortality trends, although these were not statistically significant. Glioma and unspecified tumors were the most common histological types, accounting for 55.4% and 32.8%, respectively. The proportion of microscopically verified diagnoses was 47-70% in most countries.

CONCLUSION

Although incidence and mortality rates in general were low, some countries displayed high- to intermediate-level incidence rates; under-reporting and under-ascertainment of cases could contribute to the geographic variations observed. There is a need to improve both the ascertainment of cases and the accuracy of histological diagnosis. Monitoring of brain and CNS cancers along with etiological research remain priorities.

Brain networks under attack: robustness properties and the impact of lesions

A growing number of studies approach the brain as a complex network, the so-called 'connectome'. Adopting this framework, we examine what types or extent of damage the brain can withstand-referred to as network 'robustness'-and conversely, which kind of distortions can be expected after brain lesions. To this end, we review computational lesion studies and empirical studies investigating network alterations in brain tumour, stroke and traumatic brain injury patients. Common to these three types of focal injury is that there is no unequivocal relationship between the anatomical lesion site and its topological characteristics within the brain network. Furthermore, large-scale network effects of these focal lesions are compared to those of a widely studied multifocal neurodegenerative disorder, Alzheimer's disease, in which central parts of the connectome are preferentially affected. Results indicate that human brain networks are remarkably resilient to different types of lesions, compared to other types of complex networks such as random or scale-free networks. However, lesion effects have been found to depend critically on the topological position of the lesion. In particular, damage to network hub regions-and especially those connecting different subnetworks-was found to cause the largest disturbances in network organization. Regardless of lesion location, evidence from empirical and computational lesion studies shows that lesions cause significant alterations in global network topology. The direction of these changes though remains to be elucidated. Encouragingly, both empirical and modelling studies have indicated that after focal damage, the connectome carries the potential to recover at least to some extent, with normalization of graph metrics being related to improved behavioural and cognitive functioning. To conclude, we highlight possible clinical implications of these findings, point out several methodological limitations that pertain to the study of brain diseases adopting a network approach, and provide suggestions for future research.

Analysis of Treatment Tolerance and Factors Associated with Overall Survival in Elderly Patients with Glioblastoma

BACKGROUND

As the population ages, the proportion of elderly patients with glioblastomas has increased. Recently, many researchers have focused on the treatments available to and prognoses in elderly patients with glioblastomas.

METHODS

We conducted a retrospective study of glioblastoma patients aged 60 years old or older who were treated at the Neurosurgery Center at Beijing Tiantan Hospital from 2012 to 2014. Their clinical features, immunohistochemical characteristics, treatments, and outcomes were evaluated to determine treatment tolerance and identify prognostic factors.

RESULTS

Among the 70 included patients, the median survival time was 15 months. In the univariate analysis, patients who underwent a gross total resection had longer overall survival times than patients who had a subtotal resection (P < 0.05), and patients who received postoperative adjuvant therapy had longer overall survival times than those with no postoperative adjuvant therapy (P < 0.05). The expression of the p53 protein significantly affected overall survival. Patients with low p53 protein expression had a median survival of 17 months, whereas those who had high p53 protein expression had a median survival of 11.50 months (P < 0.05). Undergoing a gross total resection, receiving postoperative adjuvant therapy and having low p53 protein expression were factors that independently contributed to longer overall survival times in multivariate analysis.

CONCLUSIONS

Maximal safe surgical resection followed by radiotherapy with concurrent and adjuvant temozolomide significantly prolonged overall survival times and was well tolerated in elderly patients with glioblastomas. In addition, low p53 protein expression was a significant favorable prognostic indicator in this population.

Glioblastoma treatment in the elderly in the temozolomide therapy era

BACKGROUND

optimal treatment of glioblastoma (gBM) in the elderly remains unclear. the impact of age on treatment planning, toxicity, and efficacy at a Canadian Cancer Centre was retrospectively reviewed.

METHODS

glioblastoma patients treated consecutively between 2004 and 2008 were reviewed. utilizing 70 years as the threshold for definition of an elderly patient, treatments and outcome were compared in younger and elderly populations.

RESULTS

four hundred and twenty one patients were included in this analysis and median overall survival (oS) for the entire cohort was 9.8 months. 290 patients were aged <70 (median age 57, range 17- 69) and 131 were aged ≥ 70 (median age 76, range 70-93). patients ≥ 70 were more likely to receive best supportive care (BSC) and all patients >70 who were treated with radiotherapy received <60 gy (P<0.001), except one. patients aged >70 demonstrated inferior survival (one year oS 16% versus 54% for those <70, hr 3.46, P<0.001). in patients treated with BSC only, age had no impact on survival (median survival two months in both groups, hr 0.89, P=0.75). for those treated with higher doses of radiotherapy (>30 gy to <60 gy), one year survival was 19% versus 24% in patients aged >70 versus <70 (hr 1.47, P=0.02) respectively.

CONCLUSION

in this retrospective single institution series, elderly patients were more likely to be treated with BSC or palliative doses of radiotherapy. randomized phase iii study results are required for guidance in treatment of this population of patients.

History of chickenpox in glioma risk: a report from the glioma international case-control study (GICC)

Varicella zoster virus (VZV) is a neurotropic α-herpesvirus that causes chickenpox and establishes life-long latency in the cranial nerve and dorsal root ganglia of the host. To date, VZV is the only virus consistently reported to have an inverse association with glioma. The Glioma International Case-Control Study (GICC) is a large, multisite consortium with data on 4533 cases and 4171 controls collected across five countries. Here, we utilized the GICC data to confirm the previously reported associations between history of chickenpox and glioma risk in one of the largest studies to date on this topic. Using two-stage random-effects restricted maximum likelihood modeling, we found that a positive history of chickenpox was associated with a 21% lower glioma risk, adjusting for age and sex (95% confidence intervals (CI): 0.65-0.96). Furthermore, the protective effect of chickenpox was stronger for high-grade gliomas. Our study provides additional evidence that the observed protective effect of chickenpox against glioma is unlikely to be coincidental. Future studies, including meta-analyses of the literature and investigations of the potential biological mechanism, are warranted.

Increased signal intensity in FLAIR sequences in the resection cavity can predict progression and progression-free survival in gliomas

OBJECTIVE

To determine if hyperintense fluid in the postsurgical cavity on follow-up fluid-attenuated inversion recovery (FLAIR) sequences can predict progression in gliomas.

MATERIAL AND METHODS

Observational study of magnetic resonance imaging signal of fluid within the post-surgical cavity in patients with glioma (grade II-IV), with surgery and follow-up between 2007 and 2012. Qualitative comparison between the signal of fluid in the cavity and of the ventricular cerebrospinal fluid (CSF) was performed on FLAIR sequences. Fluid in the cavity was classified as isointense or hyperintense compared to CSF. Double-blind reading was performed. The signal intensity was correlated with tumour progression, assessed using Response Assessment in Neuro-Oncology criteria.

RESULTS

A total of 107 patients were included, of whom 90 had high-grade gliomas. Inter-rater agreement was excellent, and intra-rater complete (k=0.94 and 1, p<.001). Hyperintense fluid in the resection cavity occurred more commonly (58.9% versus 29.4%, p=.025) and earlier (mean 4.5 versus 9.9 months, p<.001) in high-grade than in low-grade gliomas. Hyperintense fluid was associated with progression in high-grade gliomas, with a sensitivity of 65.7% (95%CI, 54.3-75.6%) and a specificity of 70.6% (95%CI, 46.6-87%), and in low-grade gliomas with a sensitivity of 50% (95%CI, 18.7-81.2%), and a specificity of 81.8% (95%CI, 51.1-96%). The positive predictive value of this sign was 90.6% (95%CI, 79.3-96.3%) for high-grade gliomas, and was higher for grade IV (93.2%, 95%CI, 87.3-99.1%) and lower for grade III (77.8%, 95%CI, 59.6-96%), and low-grade gliomas (60%, 95%CI, 22.9-88.4%). False-positives were identified in 7 patients, due to bleeding or infection. Hyperintense fluid in high-grade gliomas preceded progression in 22 patients (30.1%), with a mean of 4.1 months (SD 2.1, 95% CI, 3.2-5), and associated with poorer progression-free survival (mean 6.8 versus 11.7 months, p=.004).

CONCLUSIONS

Hyperintense fluid in the resection cavity on follow-up FLAIR sequences occurs more frequently and earlier in high-grade gliomas, and is associated with poorer progression-free survival. Hyperintense fluid is associated with disease progression, and can predict the progression of resected gliomas. False-positives due to bleeding and infection can be observed, and are easily recognizable.

The effects of antiepileptic drugs on the growth of glioblastoma cell lines

To determine the effects of antiepileptic drug compounds on glioblastoma cellular growth, we exposed glioblastoma cell lines to select antiepileptic drugs. The effects of selected antiepileptic drugs on glioblastoma cells were measured by MTT assay. For compounds showing significant inhibition, cell cycle analysis was performed. Statistical analysis was performed using SPSS. The antiepileptic compounds selected for screening included carbamazepine, ethosuximide, gabapentin, lamotrigine, levetiracetam, magnesium sulfate, oxcarbazepine, phenytoin, primidone, tiagabine, topiramate, valproic acid, and vigabatrin. Dexamethasone and temozolomide were used as a negative and positive control respectively. Our results showed temozolomide and oxcarbazepine significantly inhibited glioblastoma cell growth and reached IC50 at therapeutic concentrations. The other antiepileptic drugs screened were unable to reach IC50 at therapeutic concentrations. The metabolites of oxcarbazepine were also unable to reach IC50. Dexamethasone, ethosuximide, levetiracetam, and vigabatrin showed some growth enhancement though they did not reach statistical significance. The growth enhancement effects of ethosuximide, levetiracetam, and vigabatrin found in the study may indicate that these compounds should not be used for prophylaxis or short term treatment of epilepsy in glioblastoma. While valproic acid and oxcarbazepine were effective, the required dose of valproic acid was far above that used for the treatment of epilepsy and the metabolites of oxcarbazepine failed to reach significant growth inhibition ruling out the use of oral oxcarbazepine or valproic acid as monotherapy in glioblastoma. The possibility of using these compounds as local treatment is a future area of study.

High Toxoplasma gondii Seropositivity among Brain Tumor Patients in Korea

Toxoplasma gondii is an intracellular protozoan that can modulate the environment of the infected host. An unfavorable environment modulated by T. gondii in the brain includes tumor microenvironment. Literature has suggested that T. gondii infection is associated with development of brain tumors. However, in Korea, epidemiological data regarding this correlation have been scarce. In this study, in order to investigate the relationship between T. gondii infection and brain tumor development, we investigated the seroprevalence of T. gondii among 93 confirmed brain tumor patients (various histological types, including meningioma and astrocytoma) in Korea using ELISA. The results revealed that T. gondii seropositivity among brain tumor patients (18.3%) was significantly (P<0.05) higher compared with that of healthy controls (8.6%). The seropositivity of brain tumor patients showed a significant age-tendency, i.e., higher in younger age group, compared with age-matched healthy controls (P<0.05). In conclusion, this study supports the close relationship between T. gondii infection and incidence of brain tumors.

Malignant gliomas: old and new systemic treatment approaches

Background

Malignant (high-grade) gliomas are rapidly progressive brain tumours with very high morbidity and mortality. Until recently, treatment options for patients with malignant gliomas were limited and mainly the same for all subtypes of malignant gliomas. The treatment included surgery and radiotherapy. Chemotherapy used as an adjuvant treatment or at recurrence had a marginal role.

Conclusions

Nowadays, the treatment of malignant gliomas requires a multidisciplinary approach. The treatment includes surgery, radiotherapy and chemotherapy. The chosen approach is more complex and individually adjusted. By that, the effect on the survival and quality of life is notable higher.

Pattern of relapse of glioblastoma multiforme treated with radical radio-chemotherapy: Could a margin reduction be proposed?

To analyse the pattern of recurrence of patients treated with Stupp protocol in relation to technique, to compare in silico plans with reduced margin (1 cm) with the original ones and to analyse toxicity. 105 patients were treated: 85 had local recurrence and 68 of them were analysed. Recurrence was considered in field, marginal and distant if >80 %, 20-80 % or <20 % of the relapse volume was included in the 95 %-isodose. In silico plans were retrospectively recalculated using the same technique, fields angles and treatment planning system of the original ones. The pattern of recurrence was in field, marginal and distant in 88, 10 and 2 % respectively and was similar in in silico plans. The margin reduction appears to spare 100 cc of healthy brain by 57 Gy-volume (p = 0.02). The target coverage was worse in standard plans (pt student < 0.001), especially if the tumour was near to organs at risk (pχ2 < 0.001). PTV coverage was better with IMRT and helical-IMRT, than conformal-3D (pAnova test = 0.038). This difference was no more significant with in silico planning. A higher incidence of asthenia and leuko-encephalopathy was observed in patients with greater percentage of healthy brain included in 57 Gy-volume. No differences in the pattern of recurrence according to margins were found. The margin reduction determines sparing of healthy brain and could possibly reduce the incidence of late toxicity. Margin reduction could allow to use less sophisticated techniques, ensuring appropriate target coverage, and the choice of more costly techniques could be reserved to selected cases.

The role of the RTEL1 rs2297440 polymorphism in the risk of glioma development: a meta-analysis

The regulator of the telomere elongation helicase1 (RTEL1) gene plays a crucial role in the DNA double-stand break-repair pathway by maintaining genomic stability. Recent epidemiological studies showed that the rs2297440 polymorphism in the RTEL1 gene was a potential risk locus for glioma development, but the results were inconclusive. To clarify the association between this polymorphism and the risk of glioma, we performed a comprehensive meta-analysis. The PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure databases were systematically searched to identify all relevant published studies up to 30 August 2015. Four eligible studies were finally included. The pooled results indicated that the RTEL1 rs2297440 polymorphism moderately increased the risk of glioma in all genetic models. A comparison of the dominant model CT + CC versus TT (OR 1.40; 95 % CI 1.24-1.60; p < 0.001) indicated that having the C allele conferred a 40 % increased risk of developing glioma. In a subgroup analysis based on geographic location (Europe, Asia, and America), there was an association between the rs2297440 polymorphism and the risk of glioma in all three areas. The results of the subgroup analysis based on source of control indicated an elevated risk of glioma in population-based control studies. This meta-analysis demonstrates that the RTEL1 rs2297440 polymorphism plays a moderate, but significant role in the risk of glioma. Further studies with larger sample sizes are necessary to confirm this finding.

Dendrimer technologies for brain tumor

Despite low prevalence, brain tumors are one of the most lethal forms of cancer. Unfortunately the blood-brain barrier (BBB), a highly regulated, well coordinated and efficient barrier, checks the permeation of most of the drugs across it. Hence, crossing this barrier is one of the most significant challenges in the development of efficient central nervous system therapeutics. Surface-engineered dendrimers improve biocompatibility, drug-release kinetics and aptitude to target the BBB and/or tumors and facilitate transportation of anticancer bioactives across the BBB. This review sheds light on different aspects of brain tumors and dendrimers based on different approaches for treatment including recent research, opportunities and challenges encountered in development of novel and efficient dendrimer-based therapeutics for the treatment of brain tumors.

Anti-glioma activity and the mechanism of cellular uptake of asiatic acid-loaded solid lipid nanoparticles

Asiatic acid (AA), a pentacyclic triterpene found in Centella Asiatica, has shown neuroprotective and anti-cancer activity against glioma. However, owing to its poor aqueous solubility, effective delivery and absorption across biological barriers, in particular the blood brain barrier (BBB), are challenging. Solid lipid nanoparticles (SLNs) have shown a promising potential as a drug delivery system to carry lipophilic drugs across the BBB, a major obstacle in brain cancer therapy. Nevertheless, limited information is available about the cytotoxic mechanisms of nano-lipidic carriers with AA on normal and glioma cells. This study assessed the anti-cancer efficacy of AA-loaded SLNs against glioblastoma and their cellular uptake mechanism in comparison with SVG P12 (human foetal glial) cells. SLNs were systematically investigated for three different solid lipids; glyceryl monostearate (MS), glyceryl distearate (DS) and glyceryl tristearate (TS). The non-drug containing MS-SLNs (E-MS-SLNs) did not show any apparent toxicity towards normal SVG P12 cells, whilst the AA-loaded MS-SLNs (AA-MS-SLNs) displayed a more favourable drug release profile and higher cytotoxicity towards U87 MG cells. Therefore, MS-SLNs were chosen for further in vitro studies. Cytotoxicity studies of SLNs (± AA) were performed using MTT assay where AA-SLNs showed significantly higher cytotoxicity towards U87 MG cells than SVG P12 normal cells, as confirmed by flow cell cytometry. Cellular uptake of SLNs also appeared to be preferentially facilitated by energy-dependent endocytosis as evidenced by fluorescence imaging and flow cell cytometry. Using the Annexin V-PI double staining technique, it was found that these AA-MS-SLNs displayed concentration-dependent apoptotic activity on glioma cells, which further confirms the potential of exploiting these AA-loaded MS-SLNs for brain cancer therapy.

Astrocytes protect glioma cells from chemotherapy and upregulate survival genes via gap junctional communication

Gliomas are the most common type of primary brain tumor. Using current standard treatment regimens, the prognosis of patients with gliomas remains poor, which is predominantly due to the resistance of glioma cells to chemotherapy. The organ microenvironment has been implicated in the pathogenesis and survival of tumor cells. Thus, the aim of the present study was to test the hypothesis that astrocytes (the housekeeping cells of the brain microenvironment) may protect glioma cells from chemotherapy and to investigate the underlying mechanism. Immunofluorescent and scanning electron microscopy demonstrated that glioma cells were surrounded and infiltrated by activated astrocytes. In vitro co-culture of glioma cells with astrocytes significantly reduced the cytotoxic effects on glioma cells caused by various chemotherapeutic agents, as demonstrated by fluorescein isothiocyanate-propidium iodide flow cytometry. Transwell experiments indicated that this protective effect was dependent on physical contact and the gap junctional communication (GJC) between astrocytes and glioma cells. Microarray expression profiling further revealed that astrocytes upregulated the expression levels of various critical survival genes in the glioma cells via GJC. The results of the present study indicated that the organ microenvironment may affect the biological behavior of tumor cells and suggest a novel mechanism of resistance in glioma cells, which may be of therapeutic relevance clinically.

P2X7 receptor as predictor gene for glioma radiosensitivity and median survival

Glioblastoma multiforme (GBM) is considered the most lethal intracranial tumor and the median survival time is approximately 14 months. Although some glioma cells present radioresistance, radiotherapy has been the mainstay of therapy for patients with malignant glioma. The activation of P2X7 receptor (P2X7R) is responsible for ATP-induced death in various cell types. In this study, we analyzed the importance of ATP-P2X7R pathway in the radiotherapy response P2X7R silenced cell lines, in vivo and human tumor samples. Both glioma cell lines used in this study present a functional P2X7R and the P2X7R silencing reduced P2X7R pore activity by ethidium bromide uptake. Gamma radiation (2Gy) treatment reduced cell number in a P2X7R-dependent way, since both P2X7R antagonist and P2X7R silencing blocked the cell cytotoxicity caused by irradiation after 24h. The activation of P2X7R is time-dependent, as EtBr uptake significantly increased after 24h of irradiation. The radiotherapy plus ATP incubation significantly increased annexin V incorporation, compared with radiotherapy alone, suggesting that ATP acts synergistically with radiotherapy. Of note, GL261 P2X7R silenced-bearing mice failed in respond to radiotherapy (8Gy) and GL261 WT-bearing mice, that constitutively express P2X7R, presented a significant reduction in tumor volume after radiotherapy, showing in vivo that functional P2X7R expression is essential for an efficient radiotherapy response in gliomas. We also showed that a high P2X7R expression is a good prognostic factor for glioma radiosensitivity and survival probability in humans. Our data revealed the relevance of P2X7R expression in glioma cells to a successful radiotherapy response, and shed new light on this receptor as a useful predictor of the sensitivity of cancer patients to radiotherapy and median survival.

CCDC26, CDKN2BAS, RTEL1 and TERT Polymorphisms in pediatric brain tumor susceptibility

The role of genetic polymorphisms in pediatric brain tumor (PBT) etiology is poorly understood. We hypothesized that single nucleotide polymorphisms (SNPs) identified in genome-wide association studies (GWAS) on adult glioma would also be associated with PBT risk. The study is based on the Cefalo study, a population-based multicenter case-control study. Saliva DNA from 245 cases and 489 controls, aged 7-19 years at diagnosis/reference date, was extracted and genotyped for 29 SNPs reported by GWAS to be significantly associated with risk of adult glioma. Data were analyzed using unconditional logistic regression. Stratified analyses were performed for two histological subtypes: astrocytoma alone and the other tumor types combined. The results indicated that four SNPs, CDKN2BAS rs4977756 (p = 0.036), rs1412829 (p = 0.037), rs2157719 (p = 0.018) and rs1063192 (p = 0.021), were associated with an increased susceptibility to PBTs, whereas the TERT rs2736100 was associated with a decreased risk (p = 0.018). Moreover, the stratified analyses showed a decreased risk of astrocytoma associated with RTEL1 rs6089953, rs6010620 and rs2297440 (p trend = 0.022, p trend = 0.042, p trend = 0.029, respectively) as well as an increased risk of this subtype associated with RTEL1 rs4809324 (p trend = 0.033). In addition, SNPs rs10464870 and rs891835 in CCDC26 were associated with an increased risk of non-astrocytoma tumor subtypes (p trend = 0.009, p trend = 0.007, respectively). Our findings indicate that SNPs in CDKN2BAS, TERT, RTEL1 and CCDC26 may be associated with the risk of PBTs. Therefore, we suggest that pediatric and adult brain tumors might share common genetic risk factors and similar etiological pathways.

Stereotactic laser ablation of high-grade gliomas

Evolving research has demonstrated that surgical cytoreduction of a high-grade glial neoplasm is an important factor in improving the prognosis of these difficult tumors. Recent advances in intraoperative imaging have spurred the use of stereotactic laser ablation (laser interstitial thermal therapy [LITT]) for intracranial lesions. Among other targets, laser ablation has been used in the focal treatment of high-grade gliomas (HGGs). The revived application of laser ablation for gliomas parallels major advancements in intraoperative adjuvants and groundbreaking molecular advances in neuro-oncology. The authors review the research on stereotactic LITT for the treatment of HGGs and provide a potential management algorithm for HGGs that incorporates LITT in clinical practice.

Genetic Variations of Kinase Inserts Domain Receptor (KDR) Gene Are Associated with the Risk of Astrocytomas

Astrocytomas is one of the most common central nervous system (CNS) tumors with high mortality rate. Kinase insert domain receptor (KDR) is involved in the regulation of tumor angiogenesis, migration, and vascular permeability. The aim of the study was to explore the relationship between KDR polymorphisms and risk of astrocytomas. Blood samples were collected from 157 astrocytomas patients and 160 healthy controls. Three tag-SNPs (rs2071559C/T, rs2305948T/C, and rs1870377A/T) were identified from the International HapMap Project Databases and genotyped using the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). We evaluated the astrocytomas risk caused by individual SNPs and haplotype using odds ratios (ORs) and their 95 % confidence intervals (CIs). In the overall individual SNP analysis, the C allele of rs2071559 was correlated with an increased risk of astrocytomas. However, individuals with mutant allele A and genotype TA + AA of rs1870377 showed a protective effect against astrocytomas. Subgroup analysis based on WHO tumor grade revealed that the C allele of rs2071559 had more influence with the risk of astrocytomas in the grade III-IV (OR = 1.91) subgroup than the grade I-II (OR = 1.47) group. Genotype TT of rs2305948 was found to be significantly associated with susceptibility of astrocytomas only in the grade III-IV subgroup. The protective effect of rs1870377 did not reveal significant difference between the grade III-IV and grade I-II subgroups. Meanwhile, stratified analysis demonstrated that mutation of rs2071559 and rs2305948 could elevate the risk of astrocytomas more significantly in the subgroup of smokers than the nonsmokers. Interestingly, the protective effect of rs1870377 was more obvious in the nonsmokers than the smokers. Additionally, haplotype-specific analysis showed that haplotype CCT and CTT were related with an increased risk of astrocytomas. We found that individual with variants of rs2071559*C and rs2305948*T might significantly elevate the risk of astrocytomas, while mutants of rs1870377*A was associated with the decreased risk of astrocytomas. Further studies about ethnically diverse populations with larger sample size should be performed to confirm the correlation between KDR gene polymorphisms and risk of astrocytomas.

Associations between SOX2 and miR-200b expression with the clinicopathological characteristics and prognosis of patients with glioma

The aim of the present study was to investigate the associations between microRNA (miR)-200b and sex determining region Y-box 2 (SOX2) expression with gender, age, clinical staging and pathological staging in 123 patients with glioma. The results revealed higher miR-200b expression levels in the glioma tissue than in the normal brain tissues, and a reduction in miR-200b expression with increasing pathological grading of the gliomas. Immunohistochemistry revealed a 53.7% gross expression rate of SOX2 in the glioma tissues. SOX2 and miR-200b expression levels were significantly correlated with the histological grading of the gliomas (P<0.05); however, no associations were observed with patient gender, age, pathological classification or clinical staging of the glioma (P>0.05). In patients with grade I and II gliomas, no correlation was detected between miR-200b and SOX2, while a significant correlation was observed in grade III and IV gliomas. A median 52-month follow-up revealed 1-, 3- and 5-year gross survival rates of 82.1, 50.0 and 30.7%, respectively, in the 123 patients with a glioma. Univariate analysis revealed no association between survival rate and patient age, gender, Karnofsky Performance Scale score, histological grading or clinical staging (P>0.05). However, miR-200b and SOX2 were independent prognostic factors for glioma (P<0.05). Patients with positive SOX2 expression exhibited a significantly reduced 5-year survival rate, compared with those with negative SOX2 expression (P<0.001). Furthermore, a significantly higher 5-year survival rate was observed in patients with high miR-200b expression than those with low miR-200b expression (P<0.001). The results indicated that SOX2 and miR-200b expression levels are associated with the histological grading of gliomas, but do not correlate with patient gender or age, or the pathological classification or clinical staging of the gliomas. Thus, miR-200b and SOX2 offer useful independent prognostic factors for glioma.

Glioblastoma multiforme: Pathogenesis and treatment

Each year, about 5-6 cases out of 100,000 people are diagnosed with primary malignant brain tumors, of which about 80% are malignant gliomas (MGs). Glioblastoma multiforme (GBM) accounts for more than half of MG cases. They are associated with high morbidity and mortality. Despite current multimodality treatment efforts including maximal surgical resection if feasible, followed by a combination of radiotherapy and/or chemotherapy, the median survival is short: only about 15months. A deeper understanding of the pathogenesis of these tumors has presented opportunities for newer therapies to evolve and an expectation of better control of this disease. Lately, efforts have been made to investigate tumor resistance, which results from complex alternate signaling pathways, the existence of glioma stem-cells, the influence of the blood-brain barrier as well as the expression of 0(6)-methylguanine-DNA methyltransferase. In this paper, we review up-to-date information on MGs treatment including current approaches, novel drug-delivering strategies, molecular targeted agents and immunomodulative treatments, and discuss future treatment perspectives.

Does size matter? Minimally invasive approach in pediatric neurosurgery--a review of 125 minimally invasive surgeries in children: clinical history and operative results

OBJECTIVE

Surgery is an integral component and typically the first line of therapy for children with central nervous system tumors. Conventional aims of neurosurgery including tumor removal, management of hydrocephalus, and diagnostic sampling have been radically modified with innovative technologies such as navigational guidance, functional mapping, endoscopic surgery, second-look surgery, and physiologic imaging. The aim of the study was to investigate our operative results using minimally invasive technique in children.

METHODS

Clinical features, surgical technique and results, length of hospital stay, and complications were reviewed retrospectively. Pre- and early postoperative MRI was evaluated for degree of surgical resection. Correlation of tumor localization, lengths of hospital stay as well as surgical techniques and clinical outcome with follow-up was investigated.

RESULTS

One hundred ten patients underwent 125 tumor resections using minimally invasive approaches (image- and functional guided tailored keyhole approaches for supratentorial, retrosigmoidal, and suboccipital keyhole approaches for infratentorial lesions). Most tumors were located supratentorial (62.4 %). In 29.6 % of the cases, the surgery was performed endoscope-assisted or endoscope-controlled; neuronavigation was used in 45.6 % and ultrasound in 24 % of the cases. Astrocytomas were diagnosed in 26.4 % of cases, ependymomas in 9.6 %, and medulloblastomas in 14.4 %. Gross total resection was achieved in 60.8 %. The most common complication was CSF fistula (n = 9), and the occurrence was significantly higher in younger children (p = 0.0001) and infratentorial located tumors (p = 0.02). Surgery for posterior fossa lesions was associated with a longer hospital stay (p = 0.02) compared to surgery of supratentorial lesions. Mean follow-up was 29.7 months (range 0.3-79.1 months), and most of the children recovered during the further course of the follow-up (symptoms better or idem in 74.4 %).

CONCLUSION

In conclusion, our study shows that it is possible to achieve surgical results in the pediatric population applying minimal invasive techniques comparable to those described in the literature.

Molecular and genetic pathways in gliomas: the future of personalized therapeutics

In the last few decades, we have seen significant advances in brain imaging, which have resulted in more detailed anatomic and functional localization of gliomas in relation to the eloquent cortex, as well as improvements in microsurgical techniques and enhanced delivery of adjuvant stereotactic radiation. While these advancements have led to a relatively modest improvement in clinical outcomes for patients with malignant gliomas, much more work remains to be done. As with other types of cancer, we are now rapidly moving past the era of histopathology dictating treatment for brain tumors and into the realm of molecular diagnostics and associated targeted therapies, specifically based on the genomic architecture of individual gliomas. In this review, we discuss the current era of molecular glioma characterization and how these profiles will allow for individualized, patient-specific targeted treatments.

Bevacizumab and irinotecan in recurrent malignant glioma, a single institution experience

BACKGROUND

Treatment options of recurrent malignant gliomas are very limited and with a poor survival benefit. The results from phase II trials suggest that the combination of bevacizumab and irinotecan is beneficial.

PATIENTS AND METHODS

The medical documentation of 19 adult patients with recurrent malignant gliomas was retrospectively reviewed. All patients received bevacizumab (10 mg/kg) and irinotecan (340 mg/m(2) or 125 mg/m(2)) every two weeks. Patient clinical characteristics, drug toxicities, response rate, progression free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

Between August 2008 and November 2011, 19 patients with recurrent malignant gliomas (median age 44.7, male 73.7%, WHO performance status 0-2) were treated with bevacizumab/irinotecan regimen. Thirteen patients had glioblastoma, 5 anaplastic astrocytoma and 1 anaplastic oligoastrocytoma. With exception of one patient, all patients had initially a standard therapy with primary resection followed by postoperative chemoradiotherapy. Radiological response was confirmed after 3 months in 9 patients (1 complete response, 8 partial responses), seven patients had stable disease and three patients have progressed. The median PFS was 6.8 months (95% confidence interval [CI]: 5.3-8.3) with six-month PFS rate 52.6%. The median OS was 7.7 months (95% CI: 6.6-8.7), while six-month and twelve-month survival rates were 68.4% and 31.6%, respectively. There were 16 cases of hematopoietic toxicity grade (G) 1-2. Non-hematopoietic toxicity was present in 14 cases, all G1-2, except for one patient with proteinuria G3. No grade 4 toxicities, no thromboembolic event and no intracranial hemorrhage were observed.

CONCLUSIONS

In recurrent malignant gliomas combination of bevacizumab and irinotecan might be an active regimen with acceptable toxicity.

Association of ERCC1 rs3212986 & ERCC2 rs13181 polymorphisms with the risk of glioma

Objective:: Several previous studies have reported the role variant of ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms in the risk of glioma, but the results of these studies are inconsistent. Therefore, we aimed to conduct a meta-analysis to investigate the role of ERCC1 rs3212986 and ERCC2 rs13181 on the risk of glioma.

Methods: A comprehensive research was conducted through the databases of Pubmed, EMBASE and the China National Knowledge Infrastructure (CNKI) platforms until June 1, 2014, including 14 eligible case-control studies.

Results: Our meta-analysis found that ERCC1 rs3212986 AA genotype was significantly associated with increased risk of glioma compared with CC genotype, and the pooled OR (95%CI) was 1.29(1.07-1.55). By subgroup analysis, ERCC1 rs3212986 AA genotype was found to be significantly correlated with increased glioma risk in Chinese population (OR=1.37, 95%CI=1.07, 1.55), Similarly, we found that ERCC2 rs13181 GT and TT genotypes were significantly associated with increased risk of glioma in Chinese population, with ORs(95%CI) of 1.47(1.17-1.85) and 1.50(1.02-2.22). But ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms had no significant association with glioma risk in Caucasian populations. By begg’s funnel plot, we found that no publication bias was existed in this meta-analysis.

Conclusion: Our meta-analysis suggested that ERCC1 rs3212986 and ERCC2 rs13181 polymorphism play an important risk factor for brain tumor development in Chinese population, but no association in Caucasian populations.

MicroRNA-210 and Endoplasmic Reticulum Chaperones in the Regulation of Chemoresistance in Glioblastoma

Glioblastoma multiforme (GBM) is the commonest primary brain tumour in adults characterized by relentless recurrence due to resistance towards the standard chemotherapeutic agent temozolomide (TMZ). Prolyl 4-hydroxylase, beta polypeptide (P4HB), an endoplasmic reticulum (ER) chaperone, is known to be upregulated in TMZ-resistant GBM cells. MicroRNAs (miRNAs) are non-protein-coding transcripts that may play important roles in GBM chemoresistance. We surmised that miRNA dysregulations may contribute to P4HB upregulation, hence chemoresistance. We found that miRNA-210 (miR-210) was P4HB-targeting and was highly downregulated in TMZ-resistant GBM cells. Forced overexpression of miR-210 led to P4HB downregulation and a reduction in TMZ-resistance. A reciprocal relationship between their expressions was also verified in clinical glioma specimens. Our study is the first to demonstrate a potential link between miR-210 and ER chaperone in determining chemosensitivity in GBM. The findings have important translational implications in suggesting new directions of future studies.

The clinico-oncologic outcomes of elderly patients with glioblastoma after surgical resection followed by concomitant chemo-radiotherapy

Background

There have been controversies in the treatment of elderly patients with glioblastoma. We introduce the outcome of the treatment of elderly patients with glioblastoma comparing with younger patients.

Methods

The author's hospital database was used to identify patients with histologically confirmed glioblastoma after surgery between January 2006 and December 2013. Forty-eight patients (control group) were under age 65 and 16 patients (elderly group) were aged 65 years or over at the time of surgery.

Results

The median age of the elderly group was 71 years and control group was 50 years. Mean number of medical comorbidities was 1.8 in the elderly group vs. 0.5 in the control group. The median progression free survival (PFS) was 5.6 months and the median overall survival (OS) was 19.9 months in all patients. The elderly group had a median PFS of 4.2 months vs. 8 months for the control group (log-rank test, p=0.762). Median OS was 8.2 months in the elderly group vs. 20.9 months in the control group (log-rank test, p=0.457). Major complications occurred in 5 cases (7.8%) for all patients. The ratio of completion of concomitant chemo-radiotherapy (CCRT) was 81.3% and was the same between the two groups. In multivariable analysis, extent of resection (p=0.034) and completion of CCRT (p=0.023) were statistically significant, independent prognostic factors only for PFS in all patients by Cox proportional hazards model. Age was not an independent prognostic factor. As for OS, there was no significant factor.

Conclusion

Surgical resection and CCRT were well tolerated in elderly patients with glioblastoma, and maximal safe resection followed by timely CCRT could improve clinic-oncologic outcomes.