NOA-05 phase 2 trial of procarbazine and lomustine therapy in gliomatosis cerebri

Surgical treatment of diffuse and multi-lobes involved glioma with the assistance of a multimodal technique

Diffuse and multi-lobes involved glioma (DMG) is a rare disease, and the aim of this study was to assess the role of multimodal-assisted surgical resection of tumours combined with chemoradiotherapy and identify prognosis. Clinical data were collected from 38 patients with a diagnosis of DMG. Nineteen patients received multimodal-assisted surgical resection of tumours combined with chemoradiotherapy, and another 19 patients underwent chemoradiotherapy alone after stereotactic puncture biopsy. The clinical characteristics, magnetic resonance imaging (MRI) findings, histopathological diagnosis, progression-free survival, and overall survival of DMG patients were retrospectively analysed. Twenty-six males and 12 females were included, and the age of the participants ranged from 10 to 80 years (46.34 ± 15.61). The median overall survival in our study was 25 months, and the progression-free survival was 17 months. The extent of resection was 50.10–73.60% (62.54% ± 7.92%). The preoperative and the postoperative KPS score of the patients in the operation group showed no statistically significant difference. The results of logistic regression demonstrated that overall survival was positively associated with operative treatment + chemoradiotherapy (p = 0.003) but negatively associated with age and corpus callosal involvement (p = 0.028 and 0.022, respectively). Kaplan–Meier analyses showed that those who underwent surgical treatment had a significant progression-free and overall survival benefit compared to those who did not undergo surgical treatment (log-rank test; p = 0.011 and 0.008, respectively). Older age and involvement of the corpus callosum represent a poor prognosis in DMG patients. Multimodal-assisted surgical resection of tumours combined with chemoradiotherapy might be a treatment option for DMG. Further research is needed to obtain the clear evidence of the effect of surgical treatment.

Multifocal high-grade glioma radiotherapy safety and efficacy

Background

Multifocal manifestation of high-grade glioma is a rare disease with very unfavourable prognosis. The pathogenesis of multifocal glioma and pathophysiological differences to unifocal glioma are not fully understood. The optimal treatment of patients suffering from multifocal high-grade glioma is not defined in the current guidelines, therefore individual case series may be helpful as guidance for clinical decision-making.

Methods

Patients with multifocal high-grade glioma treated with conventionally fractionated radiation therapy (RT) in our institution with or without concomitant chemotherapy between April 2011 and April 2019 were retrospectively analysed. Multifocality was neuroradiologically assessed and defined as at least two independent contrast-enhancing foci in the MRI T1 contrast-enhanced sequence. IDH mutational status and MGMT methylation status were assessed from histopathology records. GTV, PTV as well as the V30Gy, V45Gy and D2% volumes of the brain were analysed. Overall and progression-free survival were calculated from the diagnosis until death and from start of radiation therapy until diagnosis of progression of disease in MRI for all patients.

Results

20 multifocal glioma cases (18 IDH wild-type glioblastoma cases, one diffuse astrocytic glioma, IDH wild-type case with molecular features of glioblastoma and one anaplastic astrocytoma, IDH wild-type case) were included into the analysis. Resection was performed in two cases and stereotactic biopsy only in 18 cases before the start of radiation therapy. At the start of radiation therapy patients were 61 years old in median (range 42–84 years). Histopathological examination showed IDH wild-type in all cases and MGMT promotor methylation in 11 cases (55%). Prescription schedules were 60 Gy (2 Gy × 30), 59.4 Gy (1.8 Gy × 33), 55 Gy (2.2 Gy × 25) and 50 Gy (2.5 Gy × 20) in 15, three, one and one cases, respectively. Concomitant temozolomide chemotherapy was applied in 16 cases, combined temozolomide/lomustine chemotherapy was applied in one case and concomitant bevacizumab therapy in one case. Median number of GTVs was three. Median volume of the sum of the GTVs was 26 cm³. Median volume of the PTV was 425.7 cm³ and median PTV to brain ratio 32.8 percent. Median D2% of the brain was 61.5 Gy (range 51.2–62.7) and median V30Gy and V45 of the brain were 59.9 percent (range 33–79.7) and 40.7 percent (range 14.9–64.1), respectively. Median survival was eight months (95% KI 3.6–12.4 months) and median progression free survival after initiation of RT five months (95% CI 2.8–7.2 months). Grade 2 toxicities were detected in eight cases and grade 3 toxicities in four cases consisting of increasing edema in three cases and one new-onset seizure. One grade 4 toxicity was detected, which was febrile neutropenia related to concomitant chemotherapy.

Conclusion

Conventionally fractionated RT with concomitant chemotherapy could safely be applied in multifocal high-grade glioma in this case series despite large irradiation treatment fields.

A 25-year retrospective, single center analysis of 343 WHO grade II/III glioma patients: implications for grading and temozolomide therapy

Purpose

Classification and treatment of WHO grade II/III gliomas have dramatically changed. Implementing molecular markers into the WHO classification raised discussions about the significance of grading and clinical trials showed overall survival (OS) benefits for combined radiochemotherapy. As molecularly stratified treatment data outside clinical trials are scarce, we conducted this retrospective study.

Methods

We identified 343 patients (1995–2015) with newly diagnosed WHO grade II/III gliomas and analyzed molecular markers, patient characteristics, symptoms, histology, treatment, time to treatment failure (TTF) and OS.

Results

IDH-status was available for all patients (259 mutant, 84 IDH1-R132H-non-mutant). Molecular subclassification was possible in 173 tumors, resulting in diagnosis of 80 astrocytomas and 93 oligodendrogliomas. WHO grading remained significant for OS in astrocytomas/IDH1-R132H-non-mutant gliomas (p < 0.01) but not for oligodendroglioma (p = 0.27). Chemotherapy (and temozolomide in particular) showed inferior OS compared to radiotherapy in astrocytomas (median 6.1/12.1 years; p = 0.03) and oligodendrogliomas (median 13.2/not reached (n.r.) years; p = 0.03). While radiochemotherapy improved TTF in oligodendroglioma (median radiochemotherapy n.r./chemotherapy 3.8/radiotherapy 7.3 years; p < 0.001/ = 0.06; OS data immature) the effect, mainly in combination with temozolomide, was weaker in astrocytomas (median radiochemotherapy 6.7/chemotherapy 2.3/radiotherapy 2.0 years; p < 0.001/ = 0.11) and did not translate to improved OS (median 8.4 years).

Conclusion

This is one of the largest retrospective, real-life datasets reporting treatment and outcome in low-grade gliomas incorporating molecular markers. Current histologic grading features remain prognostic in astrocytomas while being insignificant in oligodendroglioma with interfering treatment effects. Chemotherapy (temozolomide) was less effective than radiotherapy in both astrocytomas and oligodendrogliomas while radiochemotherapy showed the highest TTF in oligodendrogliomas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03511-y.

Gliomatosis Cerebri Growth Pattern: Association of Differential First-Line Treatment with Overall Survival in WHO Grade II and III Gliomas

INTRODUCTION

Gliomatosis cerebri (GC) is defined by diffuse, widespread glial tumor growth affecting three or more cerebral lobes. Previous studies in gliomas found no distinct histological or molecular GC subtype, yet the presence of GC is associated with worse median overall survival (OS). Here, we explored whether differing therapeutic strategies in first-line treatment could account for this.

METHODS

From our University Cancer Center database, 47 patients with histological diagnosis of WHO grade II or III glioma and GC imaging pattern were identified. GC criteria were confirmed by independent review. Patients with WHO grade II or III glioma with non-GC pattern served as control cohort (n = 343).

RESULTS

Within the GC patient cohort, lower WHO grade, mutated isocitrate dehydrogenase 1 (IDH1) status, and absence of contrast enhancement were associated with better OS. Compared to the control cohort, patients with GC had significantly shorter OS independent of histological diagnosis or IDH1 mutation status. Patients with GC preferentially received chemotherapy alone (62 vs. 18%), and less frequently radiochemotherapy (21 vs. 27%). OS was significantly shorter in the GC cohort compared to the non-GC cohort both for chemotherapy (3.9 vs. 7.6 years, p = 0.0085) and for combined radiochemotherapy (1.1 vs. 8.4 years, p < 0.0001). However, when only patients who received biopsy plus chemotherapy were analyzed, the differences lost statistical significance (3.5 vs. 6.6 years, p = 0.196).

CONCLUSION

We found major differences in the selection of first-line therapies of GC versus non-GC patients. Our results suggest that these differences may partly account for the worse prognosis of GC patients.

Predictive factors for overall survival in surgical cases of gliomatosis cerebri from the National Cancer Database

Gliomatosis Cerebri (GC) is a rare, aggressive, diffusely infiltrating cerebral tumor. Prognostic indicators and management strategies are currently poorly characterized. The National Cancer Database was queried for patients with histologically confirmed GC between 2004 and 2016. Demographic, tumor, and treatment characteristics were collected, including the Charlson/Deyo score, a comorbidity index adapted from the Charleston Comorbidity Index. Allowable values for the Charlson/Deyo score are 0 (no recorded comorbidities), 1, 2, and 3+ (most severe). Factors associated with overall survival were identified via bivariate log-rank tests and multivariate stepwise Cox proportional hazards models. The query returned 108 GC patients. The median age was 60.0 years, males were predominantly affected (63%), and most patients were white (86%). While 12% of cases achieved near/gross total resection and 27% of cases achieved partial resection, most surgeries were for biopsy (61%). Treatments included radiation therapy in 64% and chemotherapy in 63% of patients. The median overall survival was 15.1 (95% confidence interval [CI] = 11.1-24.8) months. On bivariate analysis, chemotherapy improved overall survival (p = 0.01) while radiation therapy (p = 0.07) and extent of resection (p = 0.48) did not. On multivariate analysis, older patients (hazard ratio [HR] = 1.07, CI = 1.03-1.11, p < 0.01) and Charlson/Deyo scores of ≥1 versus 0 (HR = 3.47, CI = 1.40-8.60, p < 0.01) had significantly increased mortality risk following surgery. In particular, the Charlson/Deyo score is a novel prognostic factor for GC that may guide clinical and surgical decision-making for this rare, rapidly fatal tumor. Further prospective studies are warranted to clarify the effects of chemotherapy versus radiation as treatment modalities for GC.

Gliomatosis cerebri mimicking diffuse demyelinating disease: Case Report

Gliomatosis Cerebri (GC) is a rareand rapidly progressive pattern of growth of diffusely infiltrating gliomas with limited treatment options. Imaging findings are usually nonspecific and can mimic other neurologic disorders, including demyelination, encephalitis, and multicentric/multifocal glioma. In this report, we describe a case of a 53-year-old female who presented with left hemiparesis, global headache, and gait ataxia with imaging features initially thought to represent demyelinating disease. A combination of conventional and advanced imaging findings with brain biopsy was utilized to make the diagnosis of GC. In patients with widespread abnormalities on brain imaging, GC should strongly be considered when cortical expansion, involvement of the septum pellucidum and elevated myoinositol levels are observed and the clinical and laboratory findings are atypical for demyelination or infection. Considering GC in such cases can facilitate early biopsy with prompt diagnosis and avoid delay in appropriate treatment.

How did lomustine become standard of care in recurrent glioblastoma?

Glioblastomas are the most common malignant primary intrinsic brain tumors. Their incidence increases with age, and males are more often affected. First-line management includes maximum safe surgical resection followed by involved-field radiotherapy plus concomitant and six cycles of maintenance temozolomide chemotherapy. Standards of care at recurrence are much less well defined. Minorities of patients are offered second surgery or re-irradiation, but data on a positive impact on survival from randomized trials are lacking. The majority of patients who are eligible for salvage therapy receive systemic treatment, mostly with nitrosourea-based regimens or, depending on availability, bevacizumab alone or in various combinations. In clinical trials, lomustine alone has been increasingly used as a control arm, assigning this drug a standard-of-care position in the setting of recurrent glioblastoma. Here we review the activity of lomustine in the treatment of diffuse gliomas of adulthood in various settings. The most compelling data for lomustine stem from three randomized trials when lomustine was combined with procarbazine and vincristine as the PCV regimen in the newly diagnosed setting together with radiotherapy; improved survival with PCV was restricted to patients with isocitrate dehydrogenase-mutant tumors. No other agent with the possible exception of regorafenib has shown superior activity to lomustine in recurrent glioblastoma, but activity is largely restricted to patients with tumors with O⁶-methylguanine DNA methyltransferase (MGMT) promoter methylation. Hematological toxicity, notably thrombocytopenia often limits adequate exposure.

Gliomatosis cerebri (GC) or GC-like? A picture to be reconsidered in neuro-oncology based on large retrospective analysis of GC series

INTRODUCTION

Gliomatosis cerebri (GC), defined until 2016 as a distinct astrocytic glioma entity, has been removed from the 2016 World Health Organization classification of tumors of the central nervous system. However, its identity is still debated.

MATERIALS AND METHODS

We retrospectively present 122 patients, including a subgroup with histology confirmation (n = 75, cohort b).

RESULTS

Radiological features showed extension limited to 3 lobes in 31%; bilateral, midline, and basal ganglia and subtentorial involvement in 95%, 52%, 84%, and 60%, respectively; and contrast enhancement in 59.5%. Perioperative mortality occurred in 4%. Histology concluded for grades II, III, and IV, respectively, in 31%, 35%, and 22% (not specified in 12%). Thirty-one percent had isocitrate dehydrogenase (IDH) 1 mutation. Treatments included radiotherapy in 51.2% and chemotherapy in 74.5%. Median overall survival was 17 months. Negative prognostic factors for survival were older age, poorer Karnofsky Performance Scale (KPS), subtentorial, midline and disseminated disease, and lack of chemotherapy, at univariate analysis. At multivariate analysis, KPS ≥ 80, chemotherapy, and subtentorial and disseminated disease remained prognostic (p < 0.0001). For cohort b, same prognostic factors were confirmed, except for midline location, at univariate analysis; at multivariate analysis, only KPS ≥ 80 and chemotherapy remained prognostic (p < 0.0001).

CONCLUSION

We described clinical, neuroimaging, management, and histomolecular features of one of the largest GC series. We identified KPS ≥ 80, radiological pattern as subtentorial localization and dissemination, and chemotherapy as prognostic factors, at multivariate analysis. Planning prospective study, associated to focused genetic assays, could help to clarify if GC has specific features that may result in the identification as a separate entity from other gliomas.

Clinical relevance of molecular subgrouping of gliomatosis cerebri per 2016 WHO classification: a clinicopathological study of 89 cases

The extremely invasive phenotypes and genotypes related to progression of gliomatosis cerebri (GC) remain unclear although GC has been removed as an independent entity from the 2016 WHO classification. Hence, categorization of GC under the current WHO molecular classification is essential, and the molecular subgroups that might contribute to GC progression should be compared with the histopathological differences between initial and new lesions identified during follow-up. Analyses of IDH1/2 and TERTp mutations and 1p/19q co-deletion, and immunohistochemistry of IDH1-R132H, ATRX, p53 and galectin-3 were performed. Anaplastic astrocytoma, IDH-wildtype (AA-IDHwt) was the common molecular subgroup (52.8%), followed by diffuse astrocytoma, IDH-wildtype (DA-IDHwt) and AA, IDH-mutant (AA-IDHmt) (each 16.9%), DA-IDHmt (7.9%), glioblastoma (GBM)-IDHwt (3.3%) and GBM-IDHmt (2.2%). Approximately 92% of the AA-IDHwt lesions progressed to histologically confirmed GBM in the newly enhanced lesions harboring the TERTp mutation and expressing galectin-3. Similar to primary GBMs, GC-related GBMs that progressed from the IDHwt subgroups showed microvascular proliferation, palisading necrosis or thrombotic occlusion, implying that a subset of IDHwt subgroups may evolve to overt GBM. Molecular subgrouping did not provide the perfect prediction for the survival of GC patients. The AA-IDHwt group showed worse overall and progression-free survival (PFS) than the AA-IDHmt group. Biopsy plus radiotherapy, chemotherapy and temozolomide treatment for DA-IDHwt, and resection plus radiotherapy and temozolomide treatment for AA-IDHwt prolonged PFS. In conclusions, majority of GC was of the AA-IDHwt subgroup, which progressed to GBM. Molecular subgroups may assist in the selection of treatment modalities, because "GC pattern" still remains as a special growth of gliomas in WHO 2016 classification without established treatment guideline.

Gliomatosis Cerebri Among Children and Adolescents: An Individual-Patient Data Meta-analysis of 182 Patients

BACKGROUND

Gliomatosis cerebri is a rare but fatal widespread infiltrating central nervous system tumor. We aimed to describe diagnostic and prognostic features of gliomatosis cerebri among children and adolescents.

METHODS

We conducted a systematic literature review for published case reports and case series on patients with histologically confirmed gliomatosis cerebri and extracted data on an individual patient level for those aged 0-18 years. Multivariable Cox proportional hazard models were fit for overall survival.

RESULTS

Following screening of 274 published studies, 182 gliomatosis cerebri patients (63% males) aged 0-18 years with individual-level data available were identified. The most common presenting symptoms were seizures (52%), focal motor deficits (36%), and headache (30%). Imaging showed bilateral hemisphere involvement in 60%, infratentorial infiltration in 39%, and a focal contrast-enhanced mass (type II gliomatosis cerebri) in 27% of cases. Anaplastic astrocytoma was the most common histologic subtype of pediatric gliomatosis cerebri, whereas MGMT promoter methylation, IDH1 mutations, and codeletion of 1p/19q were less common molecular aberrations, as compared to adult gliomatosis cerebri. In the multivariable analyses, age at diagnosis >4 years, extended central nervous system infiltration, coordination abnormalities, and cognitive decline were predictors of worse outcome. Conversely, IDH1 mutations were associated with prolonged overall survival. Chemotherapy and extended surgical resection were associated with improved outcome, whereas radiotherapy was not associated with overall survival and was inferior to chemotherapy alone.

CONCLUSION

Gliomatosis cerebri among children and adolescents presents distinct histopathologic and molecular features compared to adults. However, similar associations of chemotherapy, and, when feasible, extended surgical resection, with favorable outcomes were noted among the 2 age groups.

Gliomatosis cerebri: a consensus summary report from the Second International Gliomatosis cerebri Group Meeting, June 22-23, 2017, Bethesda, USA

Gliomatosis cerebri (GC) is an aggressive glioma characterized by an invasive growth pattern and a dismal prognosis. The low incidence and non-specific symptoms at presentation pose unique challenges for early diagnosis and disease-specific research. There is no standard of care for the treatment of patients with a GC phenotype. Understanding the biology of this entity is a critical step in determining effective treatments. Toward this end, the Second International GC Group convened at National Institutes of Health, Bethesda on June 22nd-23rd 2017. This paper summarizes the main conclusions and recommendations for research priorities to fight this fatal condition.

Wide Range of Clinical Outcomes in Patients with Gliomatosis Cerebri Growth Pattern: A Clinical, Radiographic, and Histopathologic Study

BACKGROUND

The 2016 World Health Organization Classification of Central Nervous System Tumors categorizes gliomatosis cerebri growth pattern (GC) as a subgroup of diffuse infiltrating gliomas, defined by extent of brain involvement on magnetic resonance imaging (MRI). Clinical and radiographic features in GC patients are highly heterogeneous; however, prognosis has historically been considered poor.

SUBJECTS, MATERIALS, AND METHODS

We performed a retrospective search for patients at our institution meeting radiographic criteria of primary, type I GC (defined as diffuse tumor infiltration without associated tumor mass and contrast enhancement on MRI) and analyzed their clinical, imaging, and histopathologic features.

RESULTS

A total of 34 patients met radiographic criteria of primary, type I GC, and 33 had a confirmed histologic diagnosis of an infiltrating glial neoplasm. Age >47 years at diagnosis was associated with worse overall survival (OS) compared with age ≤47 years (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.01-1.07, p = .003). Patients with grade 2 tumors demonstrated a trend for improved OS compared with those with grade 3 tumors (HR 2.65, 95% CI 0.99-7.08, p = .051). Except for brainstem involvement, extent or location of radiographic involvement did not detectably affect clinical outcome. IDH mutation status identified a subgroup of GC patients with particularly long survival up to 25 years and was associated with longer time to progression (HR 4.81, 95% CI 0.99-23.47, p = .052).

CONCLUSION

Patients with primary, type I GC do not uniformly carry a poor prognosis, even in the presence of widespread radiographic involvement. Consistent with other reports, IDH mutation status may identify patients with improved clinical outcome. Molecular characterization, rather than MRI features, may be most valuable for prognostication and management of GC patients.

IMPLICATIONS FOR PRACTICE

Patients with gliomatosis cerebri growth pattern (GC) constitute a challenge to clinicians, given their wide range of clinical, histologic, and radiographic presentation, heterogeneous outcome patterns, and the lack of consensus on a standardized treatment approach. This study highlights that radiographic extent of disease-albeit category-defining-does not detectably influence survival and that IDH mutations may impact clinical outcome. Practicing oncologists should be aware that select GC patients may demonstrate exceptionally favorable survival times and prognosticate patients based on molecular markers, rather than imaging features alone.

Procarbazine and CCNU Chemotherapy for Recurrent Glioblastoma with MGMT Promoter Methylation

BACKGROUND

While procarbazine, CCNU (lomustine), and vincristine (PCV) has been an alternative chemotherapy option for malignant gliomas, it is worth investigating whether the combination of only procarbazine and CCNU is comparable because vincristine adds toxicity with uncertain benefit. The purpose of this study was to evaluate the feasibility of procarbazine and CCNU chemotherapy for recurrent glioblastoma multiforme (GBM) with O⁶-methylguanine-DNA-methyltransferase (MGMT) promoter methylation.

METHODS

Eight patients with recurrent GBM following concurrent chemoradiotherapy and temozolomide (TMZ) adjuvant therapy were enrolled in this trial; they received no other chemotherapeutic agents or target therapy. They received CCNU (75 mg/m²) on day 1 and procarbazine (60 mg/m²) through days 11 and 24 every 4 weeks. The median cycle of CCNU and procarbazine was 3.5 (range: 2-6).

RESULTS

One patient achieved stable disease. The median progression-free survival (PFS) with procarbazine and CCNU chemotherapy was eight weeks (range: 5-73), and the PFS rates were 25% and 12.5% at 16 and 30 weeks, respectively. The median overall survival (OS) from the initial diagnosis to death was 40 months, and the median OS from the administration of procarbazine and CCNU chemotherapy to death was 9.7 months (95% confidence interval: 6.7-12.7). Serious adverse events were found at six visits, and two cases were considered to be grade 3 toxicities.

CONCLUSION

The efficacy of procarbazine and CCNU chemotherapy is not satisfactory. This study suggests the need to develop other treatment strategies for recurrent and TMZ-refractory GBM. Trial registry at ClinicalTrials.gov, NCT017337346.

Incidence and survival of gliomatosis cerebri: a population-based cancer registration study

Gliomatosis cerebri (GC) comprises a rare widespread infiltrating growth pattern of diffuse gliomas. We explored the incidence patterns and survival rates of GC in a population-based registration sample from the Surveillance, Epidemiology and End, Results database (1973-2012). GC cases (n = 176) were identified based on their International Classification of Diseases in Oncology (ICD-O-3) morphology code (9381). We calculated age-adjusted incidence rates (AIR) and evaluated temporal trends. Survival was assessed with Kaplan-Meier curves and Cox regression models. The annual AIR of GC was 0.1/million. We noted increasing trends in the preceding registration years (1973-2002; annually, + 7%) and a tendency of clinical/radiological approaches to substitute the gold-standard histological assessment for diagnosis. GC was diagnosed in the entire age spectrum (range 1-98 years), but higher incidence rates (0.43/million) were noted among the elderly (≥ 65 years). A slight male preponderance was identified (male-to-female ratio: 1.4). Median overall survival was 9 months with a 5 year survival rate of 18%. Increasing age, primary tumor location not restricted to the cerebral hemispheres and rural residence at diagnosis were identified as negative prognostic factors, whereas receipt of radiotherapy, surgical treatment, race and method of diagnosis were not associated with outcome. This first comprehensive overview of GC epidemiology exemplifies the rarity of the disease, provides evidence for male preponderance and increased incidence among the elderly and shows lower survival rates compared to the published single center reports. Expansion of registration to histological and molecular characteristics would allow emergence of clinical prognostic factors at the population level.

Gliomatosis Cerebri: Current Understanding and Controversies

Gliomatosis cerebri (GC) is a rare, extensively infiltrating glioma involving multiple contiguous lobes of the brain. This lethal disease affects all age groups, and the majority of patients have a poor outcome despite aggressive treatment. Despite its initial recognition in 1938, GC remains a controversial entity with little consensus in its definition, histology, or treatment. The majority of GC tumors are astrocytic, although mixed phenotypes have been identified. Treatment of GC is challenging as surgery is generally not an option due to the extensive areas of brain involved, the benefit of radiation therapy is unclear, and no chemotherapy has proven efficacy. Due to the rarity of the disease and its heterogeneity, both at histopathological and molecular levels, it is difficult to conduct clinical trials tailored for this diagnosis. This review summarizes our current knowledge, examines clinical studies focusing on the treatment of GC, highlights ongoing challenges, and discusses the recent molecular insights into adult and pediatric GC. We conclude that, although no longer recognized as a distinct pathological entity, GC represents a unique disease phenotype. Given the histologic and molecular overlap with other diffuse gliomas, the research emphasis should be on investigating its unique invasive biology.

Bevacizumab for Patients with Recurrent Gliomas Presenting with a Gliomatosis Cerebri Growth Pattern

Bevacizumab has been shown to improve progression-free survival and neurologic function, but failed to improve overall survival in newly diagnosed glioblastoma and at first recurrence. Nonetheless, bevacizumab is widely used in patients with recurrent glioma. However, its use in patients with gliomas showing a gliomatosis cerebri growth pattern is contentious. Due to the marked diffuse and infiltrative growth with less angiogenic tumor growth, it may appear questionable whether bevacizumab can have a therapeutic effect in those patients. However, the development of nodular, necrotic, and/or contrast-enhancing lesions in patients with a gliomatosis cerebri growth pattern is not uncommon and may indicate focal neo-angiogenesis. Therefore, control of growth of these lesions as well as control of edema and reduction of steroid use may be regarded as rationales for the use of bevacizumab in these patients. In this retrospective patient series, we report on 17 patients with primary brain tumors displaying a gliomatosis cerebri growth pattern (including seven glioblastomas, two anaplastic astrocytomas, one anaplastic oligodendroglioma, and seven diffuse astrocytomas). Patients have been treated with bevacizumab alone or in combination with lomustine or irinotecan. Seventeen matched patients treated with bevacizumab for gliomas with a classical growth pattern served as a control cohort. Response rate, progression-free survival, and overall survival were similar in both groups. Based on these results, anti-angiogenic therapy with bevacizumab should also be considered in patients suffering from gliomas with a mainly infiltrative phenotype.

Chloroethylating nitrosoureas in cancer therapy: DNA damage, repair and cell death signaling

Chloroethylating nitrosoureas (CNU), such as lomustine, nimustine, semustine, carmustine and fotemustine are used for the treatment of malignant gliomas, brain metastases of different origin, melanomas and Hodgkin disease. They alkylate the DNA bases and give rise to the formation of monoadducts and subsequently interstrand crosslinks (ICL). ICL are critical cytotoxic DNA lesions that link the DNA strands covalently and block DNA replication and transcription. As a result, S phase progression is inhibited and cells are triggered to undergo apoptosis and necrosis, which both contribute to the effectiveness of CNU-based cancer therapy. However, tumor cells resist chemotherapy through the repair of CNU-induced DNA damage. The suicide enzyme O⁶-methylguanine-DNA methyltransferase (MGMT) removes the precursor DNA lesion O⁶-chloroethylguanine prior to its conversion into ICL. In cells lacking MGMT, the formed ICL evoke complex enzymatic networks to accomplish their removal. Here we discuss the mechanism of ICL repair as a survival strategy of healthy and cancer cells and DNA damage signaling as a mechanism contributing to CNU-induced cell death. We also discuss therapeutic implications and strategies based on sequential and simultaneous treatment with CNU and the methylating drug temozolomide.

Gliomatosis cerebri: A consensus summary report from the First International Gliomatosis cerebri Group Meeting, March 26-27, 2015, Paris, France

Gliomatosis cerebri (GC) is a universally fatal extensive and diffuse infiltration of brain parenchyma by a glial tumor. Many aspects of this phenomenon remain unknown. The First International Gliomatosis cerebri Group Meeting had the following goals: refine the clinical and radiologic diagnostic criteria for GC, suggest appropriate diagnostic procedures, standardize tissue manipulation for histologic and molecular characterization, and prioritize relevant preclinical projects. Also, general treatment recommendations were outlined for the pediatric population. Importantly, this meeting was the starting point for meaningful collaborative international research projects. This review is a consensus summary of discussions shared and conclusions derived from this meeting.

Targeting Homologous Recombination by Pharmacological Inhibitors Enhances the Killing Response of Glioblastoma Cells Treated with Alkylating Drugs

Malignant gliomas exhibit a high level of intrinsic and acquired drug resistance and have a dismal prognosis. First- and second-line therapeutics for glioblastomas are alkylating agents, including the chloroethylating nitrosoureas (CNU) lomustine, nimustine, fotemustine, and carmustine. These agents target the tumor DNA, forming O⁶-chloroethylguanine adducts and secondary DNA interstrand cross-links (ICL). These cross-links are supposed to be converted into DNA double-strand breaks, which trigger cell death pathways. Here, we show that lomustine (CCNU) with moderately toxic doses induces ICLs in glioblastoma cells, inhibits DNA replication fork movement, and provokes the formation of DSBs and chromosomal aberrations. Since homologous recombination (HR) is involved in the repair of DSBs formed in response to CNUs, we elucidated whether pharmacologic inhibitors of HR might have impact on these endpoints and enhance the killing effect. We show that the Rad51 inhibitors RI-1 and B02 greatly ameliorate DSBs, chromosomal changes, and the level of apoptosis and necrosis. We also show that an inhibitor of MRE11, mirin, which blocks the formation of the MRN complex and thus the recognition of DSBs, has a sensitizing effect on these endpoints as well. In a glioma xenograft model, the Rad51 inhibitor RI-1 clearly enhanced the effect of CCNU on tumor growth. The data suggest that pharmacologic inhibition of HR, for example by RI-1, is a reasonable strategy for enhancing the anticancer effect of CNUs. Mol Cancer Ther; 15(11); 2665-78. ©2016 AACR.

Pediatric Gliomatosis Cerebri: A Review of 15 Years

Gliomatosis cerebri is a rare glial tumor that carries a poor prognosis. Seen in both adults and children, gliomatosis cerebri appears to differ in these populations as with adult versus pediatric glioblastoma. We present 10 children who either presented to the Weill Cornell Medical College or enrolled in the institution's Gliomatosis Cerebri International Registry alongside a cohort of 89 pediatric patients reported in the literature between 2000 and 2014. Age ranged from 4 months to 21 years, with a male to female ratio of 1.71. Median overall survival for patients in the registry cohort was 17 months (n = 10) and for the historic cohort was 13 months (n = 52). Overall survival was analyzed for the combined cohort and was significantly longer when presenting at age ≥ 10 (20 vs 10 months), for boys (18 vs 11 months), and with low-grade pathology (26.5 vs 12 months) but did not vary significantly by treatment approach.

Gliomatosis cerebri: no evidence for a separate brain tumor entity

Gliomatosis cerebri (GC) is presently considered a distinct astrocytic glioma entity according to the WHO classification for CNS tumors. It is characterized by widespread, typically bilateral infiltration of the brain involving three or more lobes. Genetic studies of GC have to date been restricted to the analysis of individual glioma-associated genes, which revealed mutations in the isocitrate dehydrogenase 1 (IDH1) and tumor protein p53 (TP53) genes in subsets of patients. Here, we report on a genome-wide analysis of DNA methylation and copy number aberrations in 25 GC patients. Results were compared with those obtained for 105 patients with various types of conventional, i.e., non-GC gliomas including diffuse astrocytic gliomas, oligodendrogliomas and glioblastomas. In addition, we assessed the prognostic role of methylation profiles and recurrent DNA copy number aberrations in GC patients. Our data reveal that the methylation profiles in 23 of the 25 GC tumors corresponded to either IDH mutant astrocytoma (n = 6), IDH mutant and 1p/19q codeleted oligodendroglioma (n = 5), or IDH wild-type glioblastoma including various molecular subgroups, i.e., H3F3A-G34 mutant (n = 1), receptor tyrosine kinase 1 (RTK1, n = 4), receptor tyrosine kinase 2 (classic) (RTK2, n = 2) or mesenchymal (n = 5) glioblastoma groups. Two tumors showed methylation profiles of normal brain tissue due to low tumor cell content. While histological grading (WHO grade IV vs. WHO grade II and III) was not prognostic, the molecular classification as classic/RTK2 or mesenchymal glioblastoma was associated with worse overall survival. Multivariate Cox regression analysis revealed MGMT promoter methylation as a positive prognostic factor. Taken together, DNA-based large-scale molecular profiling indicates that GC comprises a genetically and epigenetically heterogeneous group of diffuse gliomas that carry DNA methylation and copy number profiles closely matching the common molecularly defined glioma entities. These data support the removal of GC as a distinct glioma entity in the upcoming revision of the WHO classification.

[Chemotherapy of brain tumors in aduts]

The treatment of patients with brain tumors has long been the domain of neurosurgery and radiotherapy but chemotherapy is now well established as an additional treatment option for many tumor entities in neuro-oncology. This is particularly true for patients with newly diagnosed and relapsing glioblastoma and anaplastic glioma as well as the treatment of medulloblastoma and primary lymphoma of the central nervous system (CNS). In addition to purely histopathological features, treatment decisions including those for chemotherapy are now based increasingly more on molecular tumor profiling. Within the group of gliomas these markers include the methylation status of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter and the 1p/19q status, which reflects the loss of genetic material on chromosome arms 1p and 19q. The presence of a 1p/19q codeletion is associated with a better prognosis and increased sensitivity to alkylating chemotherapy in patients with anaplastic gliomas.

Procarbazine, CCNU, and Vincristine Chemotherapy in Gliomatosis Cerebri

A 49-year-old female patient was admitted due to memory disturbances. Magnetic resonance (MR) imaging suggested gliomatosis cerebri (GC), which had spread to both insular lobes, both frontal and basal ganglia and the brain stem. A stereotactic biopsy was performed at the high signal intensity area of the T2-weighted MR image, and the revealed a diffuse astrocytoma. Radiation therapy was judged not to be an appropriate treatment for the patient because of her cognitive impairment. A combinatorial chemotherapy regiment consisting of Procarbazine, CCNU, and Vincristine (PCV) was agreed upon after discussion. The patient underwent six cycles of PCV chemotherapy (a full dose was applied until the 3rd cycle, and dose then was reduced to 75% for the remaining cycles). Although the patient exhibited side effects such as bone marrow suppression and gastrointestinal symptoms, these were managed by medication. Over the 28 months following initiation of treatment, the high signal area in the right frontal and temporal lobes in the T2-weighted MR image decreased, and the patient's cognitive function [global deterioration scale (GDS) 4 points, mini-mental state examination (MMSE) 25 point] also improved (GDS 1 points, MMSE 29 points). PCV chemotherapy can therefore be an alternative therapeutic option for patients with GC who cannot be treated with radiation therapy or other chemotherapies.

Patterns of presentation and failure in patients with gliomatosis cerebri treated with partial-brain radiation therapy

BACKGROUND

The patterns of lobar involvement, optimal treatment, and disease course among patients with gliomatosis cerebri (GC) have not been fully characterized. The current study evaluates the clinical presentations and outcomes for patients with GC treated with radiation therapy (RT) at our institution.

METHODS

A total of 26 patients (25 with follow-up) with GC were diagnosed and treated between January 2004 and June 2012. Inclusion criteria consisted of brain magnetic resonance imaging and neuroradiology confirmation of contiguous involvement of ≥ 3 lobes/lobar equivalents with preservation of neural architecture. Patients were treated with either partial-brain RT to involved tumor (25 patients) or whole-brain RT (1 patient). The median RT dose was 54.0 Gray. The median follow-up was 17.3 months.

RESULTS

The median age of the patients at the time of diagnosis was 57 years. Twenty-one patients (81%) and 5 patients (19%) had 3 to 6 and ≥ 7 involved lobes/lobar equivalents, respectively. The median progression-free survival and overall survival were 7.4 months and 14.9 months, respectively. Fifteen patients experienced radiographic disease progression after partial-brain RT, 14 of whom (93%) developed infield disease recurrence. On univariate analysis, higher tumor grade and type II GC (with focal mass) were associated with a poorer progression-free survival. The extent of lobar involvement and chemotherapy were not associated with overall survival.

CONCLUSIONS

Even with partial-brain RT, nearly all disease recurrences were infield and clinical outcomes were similar to previous GC series, thereby suggesting that whole-brain RT is not necessary for this patient population. A greater number of involved lobes did not correlate with inferior outcomes. Further studies are necessary to establish more uniform and optimal treatments for this rare disease.

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.

Gliomatosis cerebri: a review

OPINION STATEMENT

Gliomatosis cerebri (GC) is an intriguing disease for several reasons. First, it is difficult to draw the border between GC and diffuse gliomas. In this regard, GC could represent the most invasive form of diffuse gliomas. Second, both in terms of histologic grading and clinical course, GC is a heterogeneous disease, ranging from rapidly evolving to slowly and somewhat indolent forms. Because of the extensive spread of the disease, surgery-outside a biopsy for diagnosis-is rarely indicated in gliomatosis cerebri. Therapeutic options include radiotherapy, generally involving the whole brain, and chemotherapy with temozolomide or nitrosoureas. Because of the rarity of the disease, no trial comparing these two modalities has been undertaken so far. Decision is, therefore, based on small retrospective noncomparative studies and expert opinions. On one hand, there is a rationale to postpone the whole brain radiotherapy because of late neurotoxicity, but on the other hand, there is also the risk that an aggressive disease evolves to intracranial hypertension making the radiotherapy hazardous or even impossible. As a consequence, the patient would lose the opportunity to receive a potentially effective treatment. In this decision, the evaluation of histologic data together with clinical and radiologic features, performance status, and molecular profile may be of help. Because radiotherapy usually involves large volumes of the brain, chemotherapy is generally preferred up front in patients with a slowly evolving disease. Conversely, in patients with rapidly (ie, over few weeks) evolving disease with neurologic deficits or when histologic features of glioblastoma are evident, whole brain radiotherapy (45 Gy with 1.8 Gy fractions), alone or associated with concomitant temozolomide, is often preferred. The value of advanced of magnetic resonance imaging and positron emission tomography techniques to predict outcome and monitoring the treatment still remains to be defined.

What do we know about IDH1/2 mutations so far, and how do we use it?

Whole genome analyses have facilitated the discovery of clinically relevant genetic alterations in a variety of diseases, most notably cancer. A prominent example of this was the discovery of mutations in isocitrate dehydrogenases 1 and 2 (IDH1/2) in a sizeable proportion of gliomas and some other neoplasms. Herein the normal functions of these enzymes, how the mutations alter their catalytic properties, the effects of their D-2-hydroxyglutarate metabolite, technical considerations in diagnostic neuropathology, implications about prognosis and therapeutic considerations, and practical applications and controversies regarding IDH1/2 mutation testing are discussed.

How molecular testing can help (and hurt) in the workup of gliomas

Advances in genetics research have greatly expanded our ability to accurately diagnose gliomas and provide more useful prognostic information. Herein specific examples are used to show how high-yield targets such as EGFR, 1p/19q, IDH1/2, MGMT, and BRAF can expand the power of the surgical neuropathologist. To avoid errors, however, the significance and controversies associated with each test must be thoroughly understood.

Mutated IDH1 is a favorable prognostic factor for type 2 gliomatosis cerebri

The prognostic significance of IDH1 mutations has been demonstrated in gliomas. It is unclear whether IDH1 mutation is also a prognostic factor in gliomatosis cerebri (GC). Primary GCs can be grouped into type 1 GCs, which have the classical diffuse growth pattern without mass formation, and type 2 GCs, which form neoplastic masses in addition to classic diffuse lesions. In this study, the prognostic relevance of IDH1/2 mutations in 74 GCs (43 type 1 and 31 type 2) was evaluated. We detected 33 (44.6%) IDH1 mutations, including R132H and R132S, by bidirectional Sanger sequencing. No mutations were detected in IDH2. The percentage of 2-year overall survival for wild-type IDH1 patients was 46 vs. 72% for patients with IDH1-mutated tumors. Mutations of IDH1 were strongly correlated with both increased overall survival (OS) and progression-free survival (PFS) in patients with type 2 GCs, and IDH1 mutations were also an independent prognostic factor predicting increased OS and PFS in type 2 GC patients in multivariate analysis. However, IDH1 mutations did not correlate with survival outcomes in patients with type 1 GCs. Finally, the subgroup of GC, which has IDH1 wild-type and additional solid component showed the worst prognosis.