Adjuvant Procarbazine, Lomustine, and Vincristine Chemotherapy in Newly Diagnosed Anaplastic Oligodendroglioma: Long-Term Follow-Up of EORTC Brain Tumor Group Study 26951

Anaplastic oligodendroglioma: a new treatment paradigm and current controversies

OPINION STATEMENT

Anaplastic oligodendroglial tumors have gained increasing interest with the emerging role of molecular markers and systemic chemotherapy during the past years. The long-term results of two landmark trials, RTOG 9402 and EORTC 26961, have resulted in a reconsideration of the appropriate therapeutic approaches for patients with these tumors. Both trials indicate that patients whose tumors harbor a 1p/19q co-deletion benefit particularly from the addition of procarbazine/lomustine (CCNU)/vincristine (PCV) chemotherapy to radiation therapy (RT). The median survival of patients with co-deleted tumors treated within the RTOG trial with PCV before irradiation was 14.7 years compared with 7.3 years of patients who received RT alone. Median overall survival has not been reached in the RT plus PCV arm of the EORTC trial, but a similar difference can be anticipated after a follow-up of more than 12 years. In contrast, no such benefit was observed for patients with tumors lacking 1p/19q co-deletion. Outside clinical trials, patients with anaplastic oligodendroglial tumors, and 1p/19q co-deletion therefore should be offered a combined treatment modality regimen, including radio- and chemotherapy. PCV, however, is associated with significant hematological toxicity and also nonhematological side effects, which probably translate into reduced quality of life for long-term survivors. Therefore, it might be warranted to replace PCV by temozolomide, which displays a more favorable side effect profile. Data from the NOA-04 study suggest that PCV and temozolomide have similar effects. However, long-term data on the benefit from temozolomide are lacking, making a definite answer on the equivalence of temozolomide and PCV in anaplastic oligodendroglioma (AO) impossible. The current evidence precludes RT alone for AO patients. Neither the RTOG nor the EORTC trial defined the role of chemotherapy alone. A comparison of combined modality treatment with chemotherapy alone followed by RT at progression is pending. Long-term follow-up of NOA-04 patients and results from future trials may help to clarify these questions. With more and more AO patients living 10 years or more, particular attention must be paid to late side effects, such as neurotoxicity, and careful monitoring is required for all treated patients.

Predictive biomarkers investigated in glioblastoma

Glioblastoma is the most aggressive primary brain tumor in adults. Consequently, new therapeutic strategies are needed. Tumor response to cytotoxic chemotherapy is heterogeneous across patients. Interestingly, predictive biomarkers of response to these classic chemotherapeutic agents have been identified in neuro-oncology (i.e., 1p/19q co-deletion, IDH mutation and O6-methylguanine DNA-methyltransferase promoter methylation). The most emblematic biomarker in glioblastoma is O6-methylguanine DNA-methyltransferase promoter methylation that predicts response to temozolomide. In parallel, innovative drugs are emerging. Some of these agents have shown some activity but in a limited number of glioblastoma patients. One of the major challenges is to identify molecular predictors of response to these smart drugs for an efficient personalized medicine. These novel agents have been tested in clinical trials enrolling glioblastoma patients. Although none of them has been validated prospectively in Phase III clinical trials, interesting molecular predictors of response to these drugs have been investigated and are presented in this review, which also reports more advanced biomarkers.

Molecular stereotactic biopsy technique improves diagnostic accuracy and enables personalized treatment strategies in glioma patients

BACKGROUND

In gliomas molecular biomarkers are increasingly gaining diagnostic, prognostic and predictive significance. Determination of biomarker status after biopsy is important as not all patients are eligible for open tumor resection. We developed and validated prospectively (6/10-12/11) a protocol allowing for both reliable determination of multiple biomarkers and representative histological diagnoses from small-sized biopsies.

METHODS

All molecular stereotactic biopsies were performed according to a detailed workflow. The selection of specimens best suited for molecular analyses was intra-operatively guided by the attending neuropathologist. Postoperative screening was done by methylation specific PCR using two distinct cryopreserved specimens to test for reproducibility of the findings and to rule out contamination. The DNA of a single best-suited specimen (1 mm(3)) was subjected to detailed molecular analysis (MGMT promoter methylation, IDH1/2 mutational status, LOH 1p and/or 19q).

RESULTS

159 consecutively enrolled untreated gliomas were analyzed (94 glioblastomas, 2 gliosarcomas, 24 anaplastic astrocytomas, 10 oligo-tumors grade II/III, 20 grade II astrocytomas and 9 pilocytic astrocytomas). Transient morbidity was 2 %. Overall, the drop-out rate due to tissue contamination was 0.4 %. Median time from biopsy to histological and molecular genetic analyses was 3 and 5 days, respectively. Distributions of the respective biomarker status for tumor subgroups were consistent with the literature. The final histological diagnosis was changed/modified in 5/159 patients according to molecular findings. Treatment after molecular biopsy was highly personalized.

CONCLUSIONS

Molecular stereotactic biopsy is feasible and safe, can be implemented in daily clinical practice, improves diagnostic precision and enables personalized treatment.

Tumour and surgery effects on cognitive functioning in high-grade glioma patients

BACKGROUND

Many high-grade glioma (HGG) patients have cognitive impairments, which impact daily functioning. Cognitive impairments can be caused by tumour-, treatment-, and patient-related factors. The effect of the tumour and of surgical resection on cognition is, however, not well known. We investigated tumour and surgical effects on cognitive functioning in patients with HGG.

METHODS

At baseline, preceding surgery, 62 patients with HGG underwent neuropsychological testing concerning seven cognitive domains: verbal and working memory, attention, executive functioning, psychomotor function, information processing speed, and visuoconstructive abilities. Thirty-nine patients were included in follow-up testing after surgery, but before subsequent treatment. Tumour size and site, use of anti-epileptic drugs and corticosteroids, and extent of resection were recorded.

RESULTS

Compared to healthy controls, cognitive functioning of patients was significantly impaired in all domains. Prior to surgery 79 % (49 of 62) of patients had cognitive impairment in at least one domain. At median follow-up of 5 weeks after surgery, 59 % (23 of 39) of patients were cognitively impaired in at least one domain. At follow-up, 49 % showed improvement, while 23 % declined. Left hemisphere tumour localization was associated with worse verbal memory (P=0.004), and larger tumours in this hemisphere with poorer executive functioning (P < 0.001). Changes in cognitive performance at follow-up relative to baseline were not related to tumour characteristics or extent of resection.

CONCLUSIONS

Tumour-related cognitive deficits are present in a majority of HGG patients preceding surgery. Surgery does not result in cognitive deterioration in the short term in most patients.

Assessing CpG island methylator phenotype, 1p/19q codeletion, and MGMT promoter methylation from epigenome-wide data in the biomarker cohort of the NOA-04 trial

BACKGROUND

Molecular biomarkers including isocitrate dehydrogenase 1 or 2 (IDH1/2) mutation, 1p/19q codeletion, and O(6)-methylguanine-DNA-methyltransferase (MGMT) promoter methylation may improve prognostication and guide treatment decisions for patients with World Health Organization (WHO) anaplastic gliomas. At present, each marker is individually tested by distinct assays. Illumina Infinium HumanMethylation450 BeadChip arrays (HM450) enable the determination of large-scale methylation profiles and genome-wide DNA copy number changes. Algorithms have been developed to detect the glioma CpG island methylator phenotype (G-CIMP) associated with IDH1/2 mutation, 1p/19q codeletion, and MGMT promoter methylation using a single assay.

METHODS

Here, we retrospectively investigated the diagnostic and prognostic performance of these algorithms in comparison to individual marker testing and patient outcome in the biomarker cohort (n = 115 patients) of the NOA-04 trial.

RESULTS

Concordance for IDH and 1p/19q status was very high: In 92% of samples, the HM450 and reference data agreed. In discordant samples, survival analysis by Kaplan-Meier and Cox regression analyses suggested a more accurate assessment of biological phenotype by the HM450 analysis. The HM450-derived MGMT-STP27 model to calculate MGMT promoter methylation probability revealed this aberration in a significantly higher fraction of samples than conventional methylation-specific PCR, with 87 of 91 G-CIMP tumors predicted as MGMT promoter-methylated. Pyrosequencing of discordant samples confirmed the HM450 assessment in 14 of 17 cases.

CONCLUSIONS

G-CIMP and 1p/19q codeletion are reliably detectable by HM450 analysis and are associated with prognosis in the NOA-04 trial. For MGMT, HM450 suggests promoter methylation in the vast majority of G-CIMP tumors, which is supported by pyrosequencing.

The level of patient-reported outcome reporting in randomised controlled trials of brain tumour patients: a systematic review

BACKGROUND

To determine the net clinical benefit of a new treatment strategy, information on both survival and patient-reported outcomes (PROs) is required. However, to make an adequately informed decision, PRO evidence should be of sufficiently high quality.

OBJECTIVE

To investigate the methodological quality of PRO reporting in randomised controlled trials (RCTs) in patients with brain tumours, and to assess the proportion of studies that should impact clinical decision-making.

METHODS

We conducted a systematic literature search in several databases covering January 2004 to March 2012. We selected relevant RCTs and retrieved the following data: (1) basic trial demographics and PRO characteristics, (2) quality of PRO reporting and (3) risk of bias. Studies that should impact clinical decision-making based on their methodological robustness were analysed systematically.

RESULTS

We identified 14 RCTs, representing over 3000 glioma patients. Only two RCTs (14%) satisfied sufficiently many key methodological criteria to provide high-quality PRO evidence, and should therefore impact clinical decision-making. Important methodological limitations in other studies were lack of reporting of the extent (43%) and reasons (86%) of missing data and statistical approaches to handle this (71%). PRO results were not interpreted in 79% of the studies and clinical significance was not discussed in 86%. Studies with high-quality PRO evidence generally showed lower risk of bias.

CONCLUSIONS

Investigators involved in brain tumour research should pay special attention to methodological challenges identified in current work. The level of PRO reporting should continue to improve in order to facilitate a critical appraisal of study results.

Morphologic spectrum of glial tumors: an increased trend towards oligodendroglial tumors in Pakistan

Background

Glial tumors are most common brain tumors in our population. While the exact etiology and pathogenesis is unknown, the evaluation of current trends in the frequency and morphology of glial tumors is imperative to constitute better diagnostic and treatment protocols. Data pertaining to frequency and spectrum of glial tumors is scarcely available in our population. The aim of this study was to determine the morphologic spectrum of glial tumors prevalent in our population.

Method

126 cases of glial tumors were retrospectively analyzed over a period of 5 years. Patients from all age groups and both genders were included in this study. Glial tumors were classified and graded according to WHO classification.

Results

Glial tumors were more common in males with a sex ratio of 2:1 and mean age of 38.26 years. Astrocytomas were most common glial tumors (51.6%) followed by oligodendrogliomas (23%). Glioblastoma was the most frequent astrocytic tumor and was incomparably frequent in older age group.

Conclusion

In our study, Oligodendrogliomas and mixed oligoastrocytomas represent major pattern of disease in comparison with available regional data. Knowledge of these changing trends and patterns of glial tumor morphology and frequency can help in improvements and applications of newly emerging diagnostic and treatment modalities.

IDH1/2 mutation detection in gliomas

Somatic mutations of isocitrate dehydrogenase 1 and 2 (IDH1/2) are strongly associated with pathological subtypes, genetic profiles, and clinical features in gliomas. The IDH1/2 status is currently regarded as one of the most important molecular markers in gliomas and should be assessed accurately and robustly. However, the methods used for IDH1/2 testing are not fully standardized. The purpose of this paper is to review the clinical significance of IDH1/2 mutations and the methods used for IDH1/2 testing. The optimal method for IDH1/2 testing varies depending on a number of factors, including the purpose, sample types, sample number, or laboratory equipment. It is therefore important to acknowledge the advantages and disadvantages of each method.

Recursive partitioning analysis of prognostic variables in newly diagnosed anaplastic oligodendroglial tumors

BACKGROUND

Anaplastic oligodendroglial tumors are rare, and median survival varies widely. Analysis of 1p19q deletion is performed commonly and is an important prognostic factor. However, age and other clinical variables also carry prognostic value, and it is unclear how to incorporate them into clinical decision making or to combine them for prognostication.

METHODS

We compiled a retrospective database of 1013 patients with newly diagnosed anaplastic oligodendrogliomas or oligoastrocytomas and performed a recursive partitioning analysis to generate independent prognostic classes among 587 patients with informative 1p19q status. Variables included for survival classification were age (continuous), history of prior low-grade glioma, 1p19q deletion status, histology (presence or absence of an astrocytic component), tumor lobe, tumor hemisphere, gender, extent of resection, postresection treatment, and performance status at diagnosis.

RESULTS

Recursive partitioning analysis identified 5 prognostic groups based on hazard similarity: class I (age <60 y, 1p19q codeleted), class II (age <43 y, not codeleted), class III (age 43-59 y, not codeleted, frontal lobe tumor or age ≥60 y, codeleted), class IV (age 43-59 y, not codeleted, not frontal lobe tumor or age 60-69 y, not codeleted), and class V (age ≥70 y, not codeleted). Survival differences were highly significant (P < .0001), with medians ranging from 9.3 years (95% CI: 8.4-16.0) for class I to 0.6 years (95% CI: 0.5-0.9) for class V.

CONCLUSIONS

These 5 distinct classification groups were defined using prognostic factors typically obtained during routine management of patients with anaplastic oligodendroglial tumors. Validation in a prospective clinical trial may better differentiate patients with respect to treatment outcome.

Medical therapy of gliomas

Medical therapies are an important part of adjunctive therapy for gliomas. In this chapter we will review the chemotherapeutic and targeted agents that have been evaluated in clinical trials in grade II-IV gliomas in the last decade. A number of randomized phase III trials were completed and reported. There has been a clear success in oligodendroglial tumors and low grade glioma. Although some progress has been made in glioblastoma, considerable work involving the multidisciplinary collaboration of basic science, translational and clinical investigators needs to be done to improve the outcome of patients with anaplastic astrocytoma and glioblastoma. In addition, tailoring treatment based on molecular cytogenetic characteristics is a major focus of research into precision based medicine for glioma.

Current and investigational drug strategies for glioblastoma

Medical treatments for glioblastoma face several challenges. Lipophilic alkylators remain the mainstay of treatment, emphasising the primacy of good blood-brain barrier penetration. Temozolomide has emerged as a major contributor to improved patient survival. The roles of procarbazine and vincristine in the procarbazine, lomustine and vincristine (PCV) schedule have attracted scrutiny and several lines of evidence now support the use of lomustine as effective single-agent therapy. Bevacizumab has had a convoluted development history, but clearly now has no major role in first-line treatment, and may even be detrimental to quality of life in this setting. In later disease, clinically meaningful benefits are achievable in some patients, but more impressively the combination of bevacizumab and lomustine shows early promise. Over the last decade, investigational strategies in glioblastoma have largely subscribed to the targeted kinase inhibitor paradigm and have mostly failed. Low prevalence dominant driver lesions such as the FGFR-TACC fusion may represent a niche role for this agent class. Immunological, metabolic and radiosensitising approaches are being pursued and offer more generalised efficacy. Finally, trial design is a crucial consideration. Progress in clinical glioblastoma research would be greatly facilitated by improved methodologies incorporating: (i) routine pharmacokinetic and pharmacodynamic assessments by preoperative dosing; and (ii) multi-stage, multi-arm protocols incorporating new therapy approaches and high-resolution biology in order to guide necessary improvements in science.

Imaging and target volume delineation in glioma

Here we review current practices in target volume delineation for radical radiotherapy planning for gliomas. Current radiotherapy planning margins for glioma are informed by historic data of recurrence patterns using radiological imaging or post-mortem studies. Radiotherapy planning for World Health Organization grade II-IV gliomas currently relies predominantly on T1-weighted contrast-enhanced magnetic resonance imaging (MRI) and T2/fluid-attenuated inversion recovery sequences to identify the gross tumour volume (GTV). Isotropic margins are added empirically for each tumour type, usually without any patient-specific individualisation. We discuss novel imaging techniques that have the potential to influence radiotherapy planning, by improving definition of the tumour extent and its routes of invasion, thus modifying the GTV and allowing anisotropic expansion to a clinical target volume better reflecting areas at risk of recurrence. Identifying the relationships of tumour boundaries to important white matter pathways and eloquent areas of cerebral cortex could lead to reduced normal tissue complications. Novel magnetic resonance approaches to identify tumour extent and invasion include: (i) diffusion-weighted magnetic resonance metrics; (ii) diffusion tensor imaging; and (iii) positron emission tomography, using radiolabelled amino acids methyl-11C-L-methionine and 18F-fluoroethyltyrosine. Novel imaging techniques may also have a role together with clinical characteristics and molecular genetic markers in predicting response to therapy. Most significant among these techniques is dynamic contrast-enhanced MRI, which uses dynamic acquisition of images after injection of intravenous contrast. A number of studies have identified changes in diffusion and microvascular characteristics occurring during the early stages of radiotherapy as powerful predictive biomarkers of outcome.

Current concepts in the surgical management of glioma patients

The scientific basis for the surgical management of patients with glioma is rapidly evolving. The infiltrative nature of these cancers precludes a surgical cure, but despite this, cytoreductive surgery remains central to high-quality patient care. In addition to tissue sampling for accurate histopathological diagnosis and molecular genetic characterisation, clinical benefit from decompression of space-occupying lesions and microsurgical cytoreduction has been reported in patients with different grades of glioma. By integrating advanced surgical techniques with molecular genetic characterisation of the disease and targeted radiotherapy and chemotherapy, it is possible to construct a programme of personalised surgical therapy throughout the patient journey. The goal of therapeutic packages tailored to each patient is to optimise patient safety and clinical outcome and must be delivered in a multidisciplinary setting. Here we review the current concepts that underlie surgical subspecialisation in the management of patients with glioma.

Oligodendroglial tumors

Oligodendroglial tumors are relatively rare, comprising approximately 5% of all glial neoplasms. Oligodendroglial tumor patients have a better prognosis than those with astrocytic neoplasms, and patients with tumors that contain 1p/19q co-deletions or IDH-1 mutations appear to be particularly sensitive to treatment. In the past decade, scientists have made significant progress in the unraveling the molecular events that relate to the pathogenesis of these neoplasms. There is considerable excitement resulting from the recent reports from two large phase III randomized trials (European Organization for Research and Treatment of Cancer [EORTC] 26951 and Radiation Therapy Oncology Group [RTOG] 9402), which disclosed that patients with newly diagnosed 1p/19q co-deleted anaplastic oligodendroglial tumors have a 7+year increase in median overall survival following chemoradiation, as compared to radiation alone. This has stimulated a renewed interest in the development of new therapeutic strategies for treatment and potential cure of oligodendroglial tumors, based on an improved scientific understanding of the molecular events involved in the pathogenesis of these neoplasms. The goal of this document is to summarize the key translational developments and recent clinical therapeutic trial data, with a correlative perspective on current and future directions.

[Personalized neurooncology]

The treatment of patients with intrinsic brain tumors is radically changing. This change is currently not (yet) signified by the use of targeted therapy in clinical practice but more by the definition of molecular markers as predictors for response to therapy which have been used for a long time. While in the past the choice of treatment has been based solely on the tumor entity and its degree of malignancy derived from histological analyses, large randomized trials have now provided a solid basis for personalized molecular-guided treatment decisions. For instance, in the German NOA-08 trial a benefit of chemotherapy with temozolomide alone was only demonstrated in a subgroup of elderly patients with malignant gliomas displaying promoter hypermethylation of the DNA repair enzyme MGMT. This is only one of several examples where molecular analysis of tumor tissue becomes clinically relevant as these analyses can and should be taken into account for treatment decisions and not, as previously, just as an additional parameter for estimating prognosis. This article illustrates the current developments in the area of personalized neurooncology and critically reviews the impact on clinical decision-making in daily practice.

Culturally and linguistically diverse patient participation in glioma research

Marginal communities, such as culturally and linguistically diverse (CALD) patients, have significantly lower rates of recruitment, accrual, and retention in cancer clinical trials. A combination of language and cultural barriers means that trial participation from CALD communities remains at suboptimal levels, which in turn favors research findings that are biased towards therapeutic effects or toxicities within the context of non-CALD populations. Here we outline some key challenges and implications for CALD patient participation in glioma research in countries such as Australia, where English is the language of governance and health services implementation. We highlight multistakeholder interventions to improve both investigator recruitment and participation of CALD communities in future glioma research, particularly in this era when global migration has come of age. Enhancing research participation of CALD communities ensures not only wider understanding of genetic heterogeneity to improve glioma outcomes but also equity in access to care.

Prognostic and predictive markers in recurrent high grade glioma; results from the BR12 randomised trial

We evaluated the prognostic and predictive value of a range of molecular changes in the setting of a randomised trial comparing standard PCV (procarbazine, CCNU (1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea) and vincristine) chemotherapy with the standard temozolomide (TMZ) 5-day (200 mg/m²/day) schedule and a 21-day (100 mg/m²/day) schedule in chemo-naïve, high-grade glioma (non-oligodendroglial tumours; WHO (World Health Organisation) grades III and IV) patients at first progression following radiotherapy.

354 samples (79.2%) from the first operation of the 447 randomised patients provided enough tumour DNA for some or all parts of the study. Genome-wide array comparative genomic hybridisation (aCGH), mutation analysis of IDH1/2 and TP53 and methylation analyses of the MGMT CpG-island was done.

84% of grade III tumours and 17% of grade IV had IDH1 or IDH2 mutations that conferred a better prognosis in both; MGMT methylation (defined as average value across 16 CpGs ≥ 10%) occurred in 75% of tumours and was also associated with improved survival. Both were of independent prognostic value after accounting for clinical factors and tumour grade. None of the molecular changes investigated gave clear evidence of a predictive benefit of TMZ over PCV or 21-day TMZ over 5-day TMZ although power was limited and a role for MGMT methylation could not be ruled out. Loss of 1p and 19q was seen in only 4 patients although hemizygous loss of 1p36 occurred in 20%.

The findings support reports that IDH1/2 mutations and MGMT methylation can be used in addition to tumour grade and clinical factors to predict survival in patients with recurrent high grade gliomas when treated with any of the therapy regimes used.

Predictive biomarkers in adult gliomas: the present and the future

PURPOSE OF REVIEW

This review summarizes recent studies on the predictive value of molecular markers in adult gliomas, including 1p/19q codeletion, MGMT methylation, IDH mutation and markers identified using omics and next-generation sequencing studies.

RECENT FINDINGS

The long-term results of the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer trials in anaplastic oligodendroglial glioma have shown that the 1p/19q codeletion predicts an overall survival benefit from early PCV (procarbazine CCNU vincristine) chemotherapy. This benefit can also be predicted using gene expression-based molecular subtypes of gliomas while the predictive value of the IDH mutation in this context requires further study. In elderly patients with glioblastoma, the analysis of MGMT methylation status in two phase III trials suggests that this alteration may guide treatment decisions; however, this finding still needs confirmation in prospective studies. Omics and next-generation sequencing studies have identified additional potential predictive markers. In particular, IDH mutations, BRAF V600E mutations and FGFR gene fusions might predict efficacy of therapies targeted against these alterations.

SUMMARY

Currently, the 1p/19q codeletion is the only well established predictive marker with clinical utility. However, it is likely that other molecular markers such as MGMT methylation, IDH mutation and those identified using omics and next-generation sequencing studies will further guide treatment decisions in adult gliomas.

Rapid and sensitive intraoperative detection of mutations in the isocitrate dehydrogenase 1 and 2 genes during surgery for glioma

Object

Intraoperative diagnosis is important in determining the strategies during surgery for glioma. Because the mutations in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes have diagnostic, prognostic, and predictive values, the authors assessed the feasibility and significance of a simplified method for the intraoperative detection of IDH1 and IDH2 gene mutations.

Methods

Rapid DNA extraction, amplification with conventional polymerase chain reaction (PCR) or co-amplification at lower denaturation temperature PCR (COLD-PCR), and fluorescence melting curve analysis with adjacent hybridization probes were performed for the intraoperative detection of IDH1 and IDH2 mutations in 18 cases of suspected nonneoplastic lesions and low- and high-grade gliomas and in 3 cases of radiation necrosis.

Results

DNA extraction for detection of the mutation took 60–65 minutes. The results of this assay showed complete correlation with that of Sanger sequencing. The sensitivity for detection of mutations in a background of wild-type genes was 12.5% and 2.5% in conventional PCR and COLD-PCR, respectively. The diagnosis of glioma was established in 3 of 5 cases in which definitive diagnosis was not obtained using frozen sections, and information was obtained for the discrimination of glioblastoma or glioblastoma with an oligodendroglioma component from anaplastic glioma or secondary glioblastoma. This assay also detected a small fraction of tumor cells with IDH1 mutation in radiation necrosis.

Conclusions

These methods provide important information for establishing the differential diagnosis between low-grade glioma and nonneoplastic lesions and the diagnosis for subtypes of high-grade glioma. Although tumor cells in radiation necrosis were detected with a high sensitivity, further investigation is necessary for clinical application in surgery for recurrent glioma.

Targetable signaling pathway mutations are associated with malignant phenotype in IDH-mutant gliomas

PURPOSE

Isocitrate dehydrogenase (IDH) gene mutations occur in low-grade and high-grade gliomas. We sought to identify the genetic basis of malignant phenotype heterogeneity in IDH-mutant gliomas.

METHODS

We prospectively implanted tumor specimens from 20 consecutive IDH1-mutant glioma resections into mouse brains and genotyped all resection specimens using a CLIA-certified molecular panel. Gliomas with cancer driver mutations were tested for sensitivity to targeted inhibitors in vitro. Associations between genomic alterations and outcomes were analyzed in patients.

RESULTS

By 10 months, 8 of 20 IDH1-mutant gliomas developed intracerebral xenografts. All xenografts maintained mutant IDH1 and high levels of 2-hydroxyglutarate on serial transplantation. All xenograft-producing gliomas harbored "lineage-defining" mutations in CIC (oligodendroglioma) or TP53 (astrocytoma), and 6 of 8 additionally had activating mutations in PIK3CA or amplification of PDGFRA, MET, or N-MYC. Only IDH1 and CIC/TP53 mutations were detected in non-xenograft-forming gliomas (P = 0.0007). Targeted inhibition of the additional alterations decreased proliferation in vitro. Moreover, we detected alterations in known cancer driver genes in 13.4% of IDH-mutant glioma patients, including PIK3CA, KRAS, AKT, or PTEN mutation or PDGFRA, MET, or N-MYC amplification. IDH/CIC mutant tumors were associated with PIK3CA/KRAS mutations whereas IDH/TP53 tumors correlated with PDGFRA/MET amplification. Presence of driver alterations at progression was associated with shorter subsequent progression-free survival (median 9.0 vs. 36.1 months; P = 0.0011).

CONCLUSION

A subset of IDH-mutant gliomas with mutations in driver oncogenes has a more malignant phenotype in patients. Identification of these alterations may provide an opportunity for use of targeted therapies in these patients. Clin Cancer Res; 20(11); 2898-909. ©2014 AACR.

Monitoring and optimising cognitive function in cancer patients: Present knowledge and future directions

The potentially detrimental effects of cancer and related treatments on cognitive functioning are emerging as a key focus of cancer survivorship research. Many patients with central nervous system (CNS) or non-CNS tumours develop cognitive problems during the course of their disease that can result in diminished functional independence. We review the state of knowledge on the cognitive functioning of patients with primary and secondary brain tumours at diagnosis, during and after therapy, and discuss current initiatives to diminish cognitive decline in these patients. Similarly, attention is paid to the cognitive sequelae of cancer and cancer therapies in patients without CNS disease. Disease and treatment effects on cognition are discussed, as well as current insights into the neural substrates and the mechanisms underlying cognitive dysfunction in these patients. In addition, rehabilitation strategies for patients with non-CNS disease confronted with cognitive dysfunction are described. Special attention is given to knowledge gaps in the area of cancer and cognition, in CNS and non-CNS diseases. Finally, we point to the important role for cooperative groups to include cognitive endpoints in clinical trials in order to accelerate our understanding and treatment of cognitive dysfunction related to cancer and cancer therapies.

Update on treatment strategies for anaplastic glioma: a review of literature

Anaplastic gliomas (AG) include 6-10% of all newly diagnoses of primary brain tumors. They have an unfavourable prognosis and, to date, there is not an established treatment universally recognized. Four recent randomized clinical trials were identified for a total of 1,170 patients (anaplastic-astrocytomas, anaplasticoligoastrocytoma, anaplastic-oligodendroglioma), in order to define the better sequence and timing of chemo-radiotherapy, Three studies compared radiotherapy (RT) treatment vs. radio-chemotherapy with procarbazine-lomustine-vincristine (PCV) or temozolomide (TMZ) or dibromodulcitol and bichloroethylnitrosurea (DBD/BCNU) and only one compared RT vs chemotherapy (CT) with PCV or TMZ. Results show no significant differences in terms of PFS/OS between RT/CT alone or combined treatment although a trend toward an improvement of OS was observed after RT + CT treatment (m-OS in RT + adjuvant PCV was 42.3 vs. 30.6 months in RT alone p=0.0003). Grade 3-4 mielotoxicity has been observed in almost all cases of patients treated with PCV + RT. None of four studies reviewed conducted a head to head comparison between PCV vs. TMZ. Only a study randomized patients to PCV/TMZ without however providing data in terms of PSF and OS between the two treatments. It found no significant differences in PFS from initial RT and adjuvant CT (PCV-TMZ) at progression compared to initial CT followed by RT at progression. The optimal treatment of AG should reasonably consider not only the histology as well as the molecular markers of the tumor, but also clinical conditions, age of patients, life expectancy, Karnofsky-performance-status and tumor resection to achieve in future the personalization of care.

Adjuvant treatment of anaplastic oligodendrogliomas and oligoastrocytomas

BACKGROUND

Standard care of adjuvant treatment for anaplastic oligodendrogliomas (AO) and anaplastic oligoastrocytomas (AOA) is not yet well defined. The benefit of adjuvant chemotherapy and radiotherapy (RT), given as single modalities or sequentially, is still unclear. Furthermore, insight into the predictive and prognostic impact of various biomarkers is surging.

OBJECTIVES

To compare postoperative sequential RT and chemotherapy to RT alone in adults with newly diagnosed AO or mixed AOA. To evaluate the predictive and prognostic impact of the following biomarkers: codeletion of chromosomes 1p and 19q, O(6)-methylguanine-DNA methyltransferase (MGMT) promotor methylation and isocitrate dehydrogenase (IDH)-1 and -2 mutations.

SEARCH METHODS

We searched the Cochrane Central Register for Controlled Trials (CENTRAL, Issue 1, 2014), MEDLINE (2006 to March week 2, 2014) and EMBASE (2006 to week 11, 2014). We scanned reference lists from relevant studies for any additional articles.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of adults with AO, AOA or anaplastic astrocytoma (AA) comparing adjuvant treatment of chemotherapy, RT, or sequential chemotherapy and RT. We excluded no specific chemotherapy regimens.

DATA COLLECTION AND ANALYSIS

We critically appraised and extracted data from relevant studies. Based on the differences in participant selection with respect to the definition of AO (two versus three high-risk anaplastic features), the inclusion of AA and sequence of treatment (RT and chemotherapy), we could not consider the results from the three RCTs for meta-analysis.

MAIN RESULTS

Three RCTs, with 931 participants, tested different neoadjuvant treatments: RT alone; sequential RT and procarbazine, lomustine and vincristine (PCV) chemotherapy; PCV chemotherapy alone; and temozolomide chemotherapy alone. None of the studies blinded participants or personnel, and, therefore, are considered at high risk of performance and detection bias. The studies were otherwise at low risk of bias. One study, the European Organisation for Research and Treatment of Cancer (EORTC) trial, demonstrated a statistically significant overall survival (OS) benefit for RT plus PCV, with a median OS of 3.5 years compared with 2.6 years in the RT alone arm (P value = 0.018). This result was reported 10 years after the conclusion of the enrolment, and was not apparent in the original 2008 Cochrane review. Furthermore, with retrospective evaluation of biomarkers, codeletion of complete chromosome arms 1p and 19q and IDH-1 or -2 mutation were independent prognostic factors for OS in two of the RCTs (Radiation Therapy Oncology Group (RTOG) and EORTC), and were predictive for OS in one trial (RTOG). The third trial (NOA-04) evaluated these biomarkers prospectively and found them prognostic for progression-free survival.

AUTHORS' CONCLUSIONS

Early PCV, either before or after RT, appears to improve OS of participants with AO or AOA. Use of biomarkers including codeletion of chromosomes 1p and 19q with or without IDH-1 or -2 mutation identify a subset of people with increased sensitivity to combined PCV and RT. The important role of biomarkers was supported in all of the RCTs examined, and prospective evaluation should be undertaken in future studies. However, PCV was associated with significant grade 3 and 4 toxicities, and whether temozolomide can be substituted for this remains unclear.

IDH1(R132H) mutation increases U87 glioma cell sensitivity to radiation therapy in hypoxia

OBJECTIVE

IDH1 codon 132 mutation (mostly Arg132His) is frequently found in gliomas and is associated with longer survival. However, it is still unclear whether IDH1 mutation renders the cell more vulnerable to current treatment, radio- and chemotherapy.

MATERIALS AND METHODS

We transduced U87 with wild type IDH1 or IDH1 (R132H) expressing lentivirus and analyzed the radiosensitivity (dose ranging 0 to 10 Gy) under normoxia (20% O2) and moderate hypoxia (1% O2).

RESULTS

We observed that IDH1 (R132H) U87 cells grow faster in hypoxia and were more sensitive to radiotherapy (in terms of cell mortality and colony formation assay) compared to nontransduced U87 and IDH1 (wt) cells. This effect was not observed in normoxia.

CONCLUSION

These data suggest that IDH1 (R132H) mutation increases radiosensitivity in mild hypoxic conditions.

Proteomic analysis of cerebrospinal fluid: toward the identification of biomarkers for gliomas

Gliomas are the most common primary brain tumors in adults and, despite advances in the understandings of glioma pathogenesis in the genetic era, they are still ineradicable, justifying the need to develop more reliable diagnostic and prognostic biomarkers for this malignancy. Because changes in cerebrospinal fluid (CSF) are suggested to be capable of sensitively reflecting pathological processes, e.g., neoplastic conditions, in the central nervous system, CSF has been deemed a valuable source for potential biomarkers screening in this era of proteomics. This systematic review focused on the proteomic analysis of glioma CSF that has been published to date and identified a total of 19 differentially expressed proteins. Further functional and protein-protein interaction assessments were performed by using Protein Analysis Through Evolutionary Relationships (PANTHER) website and Ingenuity Pathway Analysis (IPA) software, which revealed several important protein networks (e.g., IL-6/STAT-3) and four novel focus proteins (IL-6, galanin (GAL), HSPA5, and WNT4) that might be involved in glioma pathogenesis. The concentrations of these focus proteins were subsequently determined by enzyme-linked immunosorbent assay (ELISA) in an independent set of CSF and tumor cyst fluid (CF) samples. Specifically, glioblastoma (GBM) CF had significantly lower GAL, HSPA5, and WNT4 levels than CSF from different grades of glioma. In contrast, IL-6 level was significantly higher in GBM CF when compared with CSF and, among different CSF groups, was highest in GBM CSF. Therefore, these candidate protein biomarkers, identified from both the literatures and in silico analysis, may have potentials in clinical diagnosis, prognosis evaluation, treatment response monitoring, and novel therapeutic targets identification for patients with glioma.

IDH mutations: genotype-phenotype correlation and prognostic impact

IDH1/2 mutation is the most frequent genomic alteration found in gliomas, affecting 40% of these tumors and is one of the earliest alterations occurring in gliomagenesis. We investigated a series of 1305 gliomas and showed that IDH mutation is almost constant in 1p19q codeleted tumors. We found that the distribution of IDH1^R132H, IDH1^nonR132H, and IDH2 mutations differed between astrocytic, mixed, and oligodendroglial tumors, with an overrepresentation of IDH2 mutations in oligodendroglial phenotype and an overrepresentation of IDH1^nonR132H in astrocytic tumors. We stratified grade II and grade III gliomas according to the codeletion of 1p19q and IDH mutation to define three distinct prognostic subgroups: 1p19q and IDH mutated, IDH mutated—which contains mostly TP53 mutated tumors, and none of these alterations. We confirmed that IDH mutation with a hazard ratio = 0.358 is an independent prognostic factor of good outcome. These data refine current knowledge on IDH mutation prognostic impact and genotype-phenotype associations.

Treatment of malignant gliomas in elderly patients: a concise overview of the literature

Gliomas are the most frequent primary brain tumors and the incidence data has increased in the elderly population. Unfortunately, prospective studies on this population are few and so the right treatment is unknown. In the elderly patients no standard treatment has been established and therefore the optimal treatment should be individualized. We performed a review analyzing the prognostic and predictive factors, the clinical studies, and the correct management of this population.

IDH1 mutation and MGMT methylation status predict survival in patients with anaplastic astrocytoma treated with temozolomide-based chemoradiotherapy

Several molecular markers have been proposed as predictors of outcome in patients with high grade gliomas. We report a retrospective multicenter study of 97 consecutive adult patients with anaplastic astrocytoma (AA) treated with radiation therapy (RT) plus concomitant and adjuvant temozolomide (TMZ) between October 2004 and March 2012. Correlations between the isocitrate dehydrogenase 1 (IDH1) mutation and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation with survival outcomes have been analyzed. At a median follow-up time of 46 months (range 12-89 months), median and 5-year overall survival rates were 50.5 months (95 % CI, 37.8-63.2) and 38% (95 % CI, 25.7-50.7%), and median and 5-year progression-free survival rates were 36 months (95% CI, 28.5-44.0) and 22 % (95 % CI, 10-34%), respectively. IDH1 mutation and MGMT promoter methylation were present in 54 and 60% of evaluable patients, respectively. Multivariate Cox proportional hazards regression analysis showed that IDH1 mutation (P = 0.001), MGMT methylation (P = 0.01), age < 50 years (P = 0.02), and extent of resection (P = 0.04) were significantly associated with longer survival. Our study confirms the favorable prognostic value of IDH1 mutation and MGMT methylation in patients with AA treated with RT plus concomitant and adjuvant TMZ. The superiority of combined radiochemotherapy over other treatment modalities remains to be demonstrated.

Radiation therapy in neurologic disease

Radiotherapy is a primary mode of treatment of many of the disease entities seen by the neurologist. Therefore knowledge of how ionizing radiation works and when it is indicated is a crucial part of the field of Neurology. The neurologist may also be confronted with some of the side effects and complications or radiotherapy treatment. This chapter attempts to serve as a review of the current day process of radiotherapy, a brief review of biology and physics of radiation, and how it is used in the treatment diseases which are common to the Neurologist. In addition we review the more commonly seen side effects and complications of treatment which may be seen by the neurologist.

Mitotic index, microvascular proliferation, and necrosis define 3 groups of 1p/19q codeleted anaplastic oligodendrogliomas associated with different genomic alterations

BACKGROUND

The aim of this study was to correlate histological features and molecular characteristics in anaplastic oligodendrogliomas (AOs).

METHODS

The histological characteristics of 203 AO patients, enrolled in the French national network POLA, were analyzed. The genomic profiles of 191 cases were studied using genomic arrays. IDH mutational status was assessed by immunohistochemistry and direct sequencing.

RESULTS

1p/19q codeletion was present in 79% of cases and was associated with alpha-internexin expression (P < 10(-4)), IDH1/2 mutation (P < 10(-4)), chromosome 4 loss (P < 10(-3)), and better overall survival (P < 10(-4)). Based on mitotic index, microvascular proliferation (MVP), and necrosis, 3 groups of 1p/19q codeleted AOs were identified: (group 1) AO with more than 5 mitoses per 10-HPF, no MVP, and no necrosis; (group 2) AO with MVP and no necrosis; and (group 3) AO with MVP and necrosis. Compared with group 1, groups 2 and 3 AOs had a higher mean Ki-67 proliferation index and a higher rate of 9p and 9q losses. Compared with group 2, group 3 AOs had a higher number of chromosomal alterations including chromosome 4 loss. In the subgroup of 157 1p/19q codeleted AOs, chromosomal instability was associated with shorter progression-free survival (P = .024) and shorter overall survival (P = .023).

CONCLUSIONS

The present study shows that oligodendrogliomas with classic histological features remain a molecularly heterogeneous entity and should be stratified according to 1p/19q status because of its major prognostic relevance. Moreover, 1p/19q codeleted AOs are also heterogeneous. Interestingly, mitotic index, MVP, and necrosis help to classify them into 3 groups associated with distinct genomic alterations.

An overview of fotemustine in high-grade gliomas: from single agent to association with bevacizumab

Fotemustine is a third-generation nitrosourea showing efficacy in various types of tumors such as melanoma and glioma. We reviewed the most important studies on fotemustine treatment in glioma patients analyzing its pharmacological profile and its activity and safety. Fotemustine was used as single agent or in association with new targeted drugs such as bevacizumab; fotemustine was used both as first-line chemotherapy before temozolomide era and in refractory-temozolomide patients during temozolomide era. Finally, analyzing and comparing the activity and safety of fotemustine alone or in combination with bevacizumab versus other nitrosoureas such as lomustine, we may suggest that the combination treatment with bevacizumab and fotemustine may be active and tolerable in patients with high grade gliomas.

Central nervous system cancers

Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at NCCN. org, contains recommendations on additional subtypes.

Prognostic and predictive biomarkers in adult and pediatric gliomas: toward personalized treatment

It is increasingly clear that both adult and pediatric glial tumor entities represent collections of neoplastic lesions, each with individual pathological molecular events and treatment responses. In this review, we discuss the current prognostic biomarkers validated for clinical use or with future clinical validity for gliomas. Accurate prognostication is crucial for managing patients as treatments may be associated with high morbidity and the benefits of high risk interventions must be judged by the treating clinicians. We also review biomarkers with predictive validity, which may become clinically relevant with the development of targeted therapies for adult and pediatric gliomas.

Malignant gliomas: current perspectives in diagnosis, treatment, and early response assessment using advanced quantitative imaging methods

Malignant gliomas consist of glioblastomas, anaplastic astrocytomas, anaplastic oligodendrogliomas and anaplastic oligoastrocytomas, and some less common tumors such as anaplastic ependymomas and anaplastic gangliogliomas. Malignant gliomas have high morbidity and mortality. Even with optimal treatment, median survival is only 12–15 months for glioblastomas and 2–5 years for anaplastic gliomas. However, recent advances in imaging and quantitative analysis of image data have led to earlier diagnosis of tumors and tumor response to therapy, providing oncologists with a greater time window for therapy management. In addition, improved understanding of tumor biology, genetics, and resistance mechanisms has enhanced surgical techniques, chemotherapy methods, and radiotherapy administration. After proper diagnosis and institution of appropriate therapy, there is now a vital need for quantitative methods that can sensitively detect malignant glioma response to therapy at early follow-up times, when changes in management of nonresponders can have its greatest effect. Currently, response is largely evaluated by measuring magnetic resonance contrast and size change, but this approach does not take into account the key biologic steps that precede tumor size reduction. Molecular imaging is ideally suited to measuring early response by quantifying cellular metabolism, proliferation, and apoptosis, activities altered early in treatment. We expect that successful integration of quantitative imaging biomarker assessment into the early phase of clinical trials could provide a novel approach for testing new therapies, and importantly, for facilitating patient management, sparing patients from weeks or months of toxicity and ineffective treatment. This review will present an overview of epidemiology, molecular pathogenesis and current advances in diagnoses, and management of malignant gliomas.

Loss of CIC and FUBP1 expressions are potential markers of shorter time to recurrence in oligodendroglial tumors

Combined deletion of chromosomes 1p and 19q is a prognostic marker in oligodendroglial tumors. Recent studies in oligodendroglial tumors have unveiled recurrent mutations of CIC (homolog of Drosophila capicua) and FUBP1 (far upstream element binding protein 1) that are located on 19q13 and 1p31, respectively. However, the impact of CIC and FUBP1 mutations on their protein expressions has not been examined. The aims of this study were to correlate the expression patterns of CIC and FUBP1 with their mutation profiles and to evaluate the clinical relevance of these molecular markers in 55 oligodendroglial tumors diagnosed in 47 adult patients. Using direct sequencing, somatic mutations of CIC and FUBP1 were identified in 47% (22/47) and 16% (7/45) of oligodendroglial tumors, respectively. Immunohistochemical analysis revealed loss of CIC or FUBP1 protein expression in 36% (20/55) and 16% (9/55) of oligodendroglial tumors examined. Somatic mutation was significantly associated with absent protein expression for both genes (CIC, P=0.01; FUBP1, P=0.00001). Four tumors with undetectable CIC mutations exhibited absent CIC expression, suggesting that CIC inactivation could be mediated by mechanisms other than mutations and genomic loss. Univariate survival analysis revealed that 1p/19q codeletion was significantly associated with overall survival (P=0.05). Loss of CIC expression was significantly correlated with shorter progression-free survival (P=0.03), whereas CIC alteration (mutation or null expression) with worse overall survival (P=0.05). Absent FUBP1 expression was linked with unfavorable progression-free survival (P=0.02) and overall survival (P=0.01). In 16 tumors with 1p/19q codeletion, CIC mutation was associated with unfavorable survival (P=0.01). There was a correlation between lack of CIC or FUBP1 expression and poor progression-free survival (P=0.004; P=0.0003). No molecular markers showed association with survival in oligodendroglial tumors lacking 1p/19q codeletion. We conclude that absent CIC and FUBP1 expressions are potential markers of shorter time to recurrence and CIC mutation a potential marker of worse prognosis, especially in tumors carrying 1p/19q codeletion.

Chemotherapy and immunotherapy of brain tumors: what the epileptologist must know

I present an overview of therapy for the most common brain tumors encountered in clinical practice if adult patients. Current therapy paradigms and evolving therapies are reviewed. The introduction of non-enzyme-inducing antiepileptic drugs (NEIADs) has simplified the approach to combined medical treatment of epilepsy and brain tumors, but the major interactions between enzyme-inducing antiepileptic drugs (EIAEDs) are included, to serve as guidance in selecting these medications if they are required.

Benefit from procarbazine, lomustine, and vincristine in oligodendroglial tumors is associated with mutation of IDH

PURPOSE

Patients with 1p/19q codeleted anaplastic oligodendroglial tumors who participated in RTOG (Radiation Therapy Oncology Group) 9402 lived much longer after chemoradiotherapy (CRT) than radiation therapy (RT) alone. However, some patients with noncodeleted tumors also benefited from CRT; survival curves separated after the median had been reached, and significantly more patients lived ≥ 10 years after CRT than RT. Thus, 1p/19q status may not identify all responders to CRT.

PATIENTS AND METHODS

Using trial data, we inquired whether an IDH mutation or germ-line polymorphism associated with IDH-mutant gliomas identified the patients in RTOG 9402 who benefited from CRT.

RESULTS

IDH status was evaluable in 210 of 291 patients; 156 (74%) had mutations. rs55705857 was evaluable in 245 patients; 76 (31%) carried the G risk allele. Both were associated with longer progression-free survival after CRT, and mutant IDH was associated with longer overall survival (9.4 v 5.7 years; hazard ratio [HR], 0.59; 95% CI, 0.40 to 0.86; P = .006). For those with wild-type tumors, CRT did not prolong median survival (1.3 v 1.8 years; HR, 1.14; 95% CI, 0.63 to 2.04; P = .67) or 10-year survival rate (CRT, 6% v RT, 4%). Patients with codeleted mutated tumors (14.7 v 6.8 years; HR, 0.49; 95% CI, 0.28 to 0.85; P = .01) and noncodeleted mutated tumors (5.5 v 3.3 years; HR, 0.56; 95% CI, 0.32 to 0.99; P < .05) lived longer after CRT than RT.

CONCLUSION

IDH mutational status identified patients with oligodendroglial tumors who did (and did not) benefit from alkylating-agent chemotherapy with RT. Although patients with codeleted tumors lived longest, patients with noncodeleted IDH-mutated tumors also lived longer after CRT.

Towards optimizing the sequence of bevacizumab and nitrosoureas in recurrent malignant glioma

Studies on the monoclonal VEGF-A antibody bevacizumab gave raise to questions regarding the lack of an overall survival benefit, the optimal timing in the disease course and potential combination and salvage therapies. We retrospectively assessed survival, radiological progression type on bevacizumab and efficacy of salvage therapies in 42 patients with recurrent malignant gliomas who received bevacizumab and nitrosourea sequentially. 15 patients received bevacizumab followed by nitrosourea at progression and 27 patients vice versa. Time to treatment failure, defined as time from initiation of one to failure of the other treatment, was similar in both groups (9.6 vs. 9.2 months, log rank p = 0.19). Progression-free survival on nitrosoureas was comparable in both groups, while progression-free survival on bevacizumab was longer in the group receiving bevacizumab first (5.3 vs. 4.1 months, log rank p = 0.03). Survival times were similar for patients with grade III (n = 9) and grade IV (n = 33) tumors. Progression-free survival on bevacizumab for patients developing contrast-enhancing T1 progression was longer than for patients who displayed a non-enhancing T2 progression. However, post-progression survival times after bevacizumab failure were not different. Earlier treatment with bevacizumab was not associated with better outcome in this series. The fact that earlier as compared to later bevacizumab treatment does not result in a different time to treatment failure highlights the challenge for first-line or recurrence trials with bevacizumab to demonstrate an overall survival benefit if crossover of bevacizumab-naïve patients after progression occurs.

Controversies over the diagnosis of oligodendroglioma: a report from the satellite workshop at the 4th international symposium of brain tumor pathology, Nagoya Congress Center, May 23, 2012

With the goal of discussing how the neuropathology community should resolve the controversy over the diagnosis of oligodendroglioma, this Satellite Workshop reflects the collaboration between two invited keynote speakers: Dr. Johan M. Kros of the Erasmus Medical Center and Dr. Kenneth D. Aldape of the University of Texas MD Anderson Cancer Center and the Organizing Committee of the Japanese Society of Brain Tumor Pathology. In the first half of the workshop, the keynote speakers reviewed the current status of the pathology and genetics of oligodendroglioma. In the second half, six debatable cases that exemplify the current controversies over the diagnosis of oligodendroglioma were presented. The consensus diagnoses in these six cases, which have been reviewed by members of the Society, were opened to discussion and comments by the speakers. These cases highlight unresolved issues in the WHO 2007 classification of oligodendrogliomas, particularly the discordance between morphology and genetics. To achieve synchronization between phenotypes and genotypes, the neuropathology diagnosis should focus on the classic features of oligodendrogliomas that are highly correlated with the genetic background.