PCV chemotherapy for recurrent oligodendrogliomas and oligoastrocytomas

Disease Assessments in Patients with Glioblastoma

PURPOSE OF REVIEW

The neuro-oncology team faces a unique challenge when assessing treatment response in patients diagnosed with glioblastoma. Magnetic resonance imaging (MRI) remains the standard imaging modality for measuring therapeutic response in both clinical practice and clinical trials. However, even for the neuroradiologist, MRI interpretations are not straightforward because of tumor heterogeneity, as evidenced by varying degrees of enhancement, infiltrating tumor patterns, cellular densities, and vasogenic edema. The situation is even more perplexing following therapy since treatment-related changes can mimic viable tumor. Additionally, antiangiogenic therapies can dramatically decrease contrast enhancement giving the false impression of decreasing tumor burden. Over the past few decades, several approaches have emerged to augment and improve visual interpretation of glioblastoma response to therapeutics. Herein, we summarize the state of the art for evaluating the response of glioblastoma to standard therapies and investigational agents as well as challenges and future directions for assessing treatment response in neuro-oncology.

RECENT FINDINGS

Monitoring glioblastoma responses to standard therapy and novel agents has been fraught with many challenges and limitations over the past decade. Excitingly, new promising methods are emerging to help address these challenges. Recently, the Response Assessment in Neuro-Oncology (RANO) working group proposed an updated response criteria (RANO 2.0) for the evaluation of all grades of glial tumors regardless of IDH status or therapies being evaluated. In addition, advanced neuroimaging techniques, such as histogram analysis, parametric response maps, morphometric segmentation, radio pharmacodynamics approaches, and the integrating of amino acid radiotracers in the tumor evaluation algorithm may help resolve equivocal lesion interpretations without operative intervention. Moreover, the introduction of other techniques, such as liquid biopsy and artificial intelligence could complement conventional visual assessment of glioblastoma response to therapies. Neuro-oncology has evolved over the past decade and has achieved significant milestones, including the establishment of new standards of care, emerging therapeutic options, and novel clinical, translational, and basic research. More recently, the integration of histopathology with molecular features for tumor classification has marked an important paradigm shift in brain tumor diagnosis. In a similar manner, treatment response monitoring in neuro-oncology has made considerable progress. While most techniques are still in their inception, there is an emerging body of evidence for clinical application. Further research will be critically important for the development of impactful breakthroughs in this area of the field.

Advanced Imaging Techniques for Newly Diagnosed and Recurrent Gliomas

Management of gliomas following initial diagnosis requires thoughtful presurgical planning followed by regular imaging to monitor treatment response and survey for new tumor growth. Traditional MR imaging modalities such as T1 post-contrast and T2-weighted sequences have long been a staple of tumor diagnosis, surgical planning, and post-treatment surveillance. While these sequences remain integral in the management of gliomas, advances in imaging techniques have allowed for a more detailed characterization of tumor characteristics. Advanced MR sequences such as perfusion, diffusion, and susceptibility weighted imaging, as well as PET scans have emerged as valuable tools to inform clinical decision making and provide a non-invasive way to help distinguish between tumor recurrence and pseudoprogression. Furthermore, these advances in imaging have extended to the operating room and assist in making surgical resections safer. Nevertheless, surgery, chemotherapy, and radiation treatment continue to make the interpretation of MR changes difficult for glioma patients. As analytics and machine learning techniques improve, radiomics offers the potential to be more quantitative and personalized in the interpretation of imaging data for gliomas. In this review, we describe the role of these newer imaging modalities during the different stages of management for patients with gliomas, focusing on the pre-operative, post-operative, and surveillance periods. Finally, we discuss radiomics as a means of promoting personalized patient care in the future.

Oligodendroglioma: A Review of Management and Pathways

Anaplastic oligodendrogliomas are a type of glioma that occurs primarily in adults but are also found in children. These tumors are genetically defined according to the mutations they harbor. Grade II and grade III tumors can be differentiated most of the times by the presence of anaplastic features. The earliest regimen used for the treatment of these tumors was procarbazine, lomustine, and vincristine. The treatment modalities have shifted over time, and recent studies are considering immunotherapy as an option as well. This review assesses the latest management modalities along with the pathways involved in the pathogenesis of this malignancies.

Seizure Outcome After Surgery for Insular High-Grade Glioma

BACKGROUND

The insular cortex is an eloquent island of mesocortex surrounded by vital structures making this region relatively challenging to neurosurgeons. Historically, lesions in this region were considered too high risk to approach given the strong chance of poor surgical outcome. Advances in recent decades have meant that surgeons can more safely access this eloquent region. Seizure outcome after excision of insular low-grade gliomas is well reported, but little is known about seizure outcomes after excision of insular high-grade gliomas.

METHODS

A retrospective analysis was performed of all patients presenting with new-onset seizures during 2015-2019 who underwent excision of an insular high-grade glioma at 3 regional neurosurgical centers in the United Kingdom.

RESULTS

We identified 38 patients with a mean (SD) age of 45.7 (15.3) years with median follow-up of 21 months. At long-term follow-up, of 38 patients, 23 were seizure-free (Engel class I), 2 had improved seizures (Engel class II), 6 had poor seizure control (Engel class III/IV), and 7 died.

CONCLUSIONS

Excision of insular high-grade gliomas is safe and results in excellent postoperative seizure control.

Central Nervous System Cancers, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of adult CNS cancers ranging from noninvasive and surgically curable pilocytic astrocytomas to metastatic brain disease. The involvement of an interdisciplinary team, including neurosurgeons, radiation therapists, oncologists, neurologists, and neuroradiologists, is a key factor in the appropriate management of CNS cancers. Integrated histopathologic and molecular characterization of brain tumors such as gliomas should be standard practice. This article describes NCCN Guidelines recommendations for WHO grade I, II, III, and IV gliomas. Treatment of brain metastases, the most common intracranial tumors in adults, is also described.

Recent developments and future directions in adult lower-grade gliomas: Society for Neuro-Oncology (SNO) and European Association of Neuro-Oncology (EANO) consensus

The finding that most grades II and III gliomas harbor isocitrate dehydrogenase (IDH) mutations conveying a relatively favorable and fairly similar prognosis in both tumor grades highlights that these tumors represent a fundamentally different entity from IDH wild-type gliomas exemplified in most glioblastoma. Herein we review the most recent developments in molecular neuropathology leading to reclassification of these tumors based upon IDH and 1p/19q status, as well as the potential roles of methylation profiling and deletional analysis of cyclin-dependent kinase inhibitor 2A and 2B. We discuss the epidemiology, clinical manifestations, benefit of surgical resection, and neuroimaging features of lower-grade gliomas as they relate to molecular subtype, including advanced imaging techniques such as 2-hydroxyglutarate magnetic resonance spectroscopy and amino acid PET scanning. Recent, ongoing, and planned studies of radiation therapy and both cytotoxic and targeted chemotherapies are summarized, including both small molecule and immunotherapy approaches specifically targeting the mutant IDH protein.

Chemotherapy and diffuse low-grade gliomas: a survey within the European Low-Grade Glioma Network

BACKGROUND

Diffuse low-grade gliomas (DLGGs) are rare and incurable tumors. Whereas maximal safe, functional-based surgical resection is the first-line treatment, the timing and choice of further treatments (chemotherapy, radiation therapy, or combined treatments) remain controversial.

METHODS

An online survey on the management of DLGG patients was sent to 28 expert centers from the European Low-Grade Glioma Network (ELGGN) in May 2015. It contained 40 specific questions addressing the modalities of use of chemotherapy in these patients.

RESULTS

The survey demonstrated a significant heterogeneity in practice regarding the initial management of DLGG patients and the use of chemotherapy. Interestingly, radiation therapy combined with the procarbazine, CCNU (lomustine), and vincristine regimen has not imposed itself as the gold-standard treatment after surgery, despite the results of the Radiation Therapy Oncology Group 9802 study. Temozolomide is largely used as first-line treatment after surgical resection for high-risk DLGG patients, or at progression.

CONCLUSIONS

The heterogeneity in the management of patients with DLGG demonstrates that many questions regarding the postoperative strategy and the use of chemotherapy remain unanswered. Our survey reveals a high recruitment potential within the ELGGN for retrospective or prospective studies to generate new data regarding these issues.

Seizure response to temozolomide chemotherapy in patients with WHO grade II oligodendroglioma: a single-institution descriptive study

Background

Tumor-related epilepsy (TRE) is common in patients with low-grade oligodendrogliomas. TRE is difficult to control despite multiple antiepileptic drugs (AEDs) in up to 30% of patients. Chemotherapy has been used for treatment to avoid potential radiotherapy-related neurotoxicity. This study evaluates the effect of temozolomide on seizure frequency in a homogeneous group with World Health Organization (WHO) grade II oligodendrogliomas.

Methods

A retrospective analysis was conducted of adult patients with WHO grade II oligodendrogliomas and TRE followed at Memorial Sloan Kettering between 2005 and 2015 who were treated with temozolomide alone either as initial treatment or for disease progression. All had seizures 3 months prior to starting temozolomide. Seizure frequency was reviewed every 2 cycles and at the end of temozolomide treatment. Seizure reduction of ≥50% compared to baseline was defined as improvement.

Results

Thirty-nine individuals met inclusion criteria. Median follow-up since starting temozolomide was 6 years (0.8-13 years). Reduction in seizure frequency occurred in 35 patients (89.7%). Improvement was independent of AED regimen adjustments or prior antitumor treatment in 16 (41%); of these, AED dosage was successfully reduced or completely eliminated in 10 (25.6%). Twenty-five patients (64.1%) remained on a stable AED regimen. The majority (n = 32, 82%) had radiographically stable disease, 5 (12.8%) had objective radiographic response, and 2 (5.2%) had disease progression.

Conclusions

Temozolomide may result in reduced seizure frequency, and permit discontinuation of AEDs in patients with WHO II oligodendroglioma. Improvement was observed irrespective of objective tumor response on MRI, emphasizing the importance of incorporating seizure control in assessing response to tumor-directed therapy.

Case Report: Clinical Outcome and Image Response of Two Patients With Secondary High-Grade Glioma Treated With Chemoradiation, PCV, and Cannabidiol

We describe two patients with a confirmed diagnosis of high-grade gliomas (grades III/IV), both presenting with O6-methylguanine-DNA methyltransferase (MGMT) methylated and isocitrate dehydrogenase (IDH-1) mutated who, after subtotal resection, were submitted to chemoradiation and followed by PCV, a multiple drug regimen (procarbazine, lomustine, and vincristine) associated with cannabidiol (CBD). Both patients presented with satisfactory clinical and imaging responses at periodic evaluations. Immediately after chemoradiation therapy, one of the patients presented with an exacerbated and precocious pseudoprogression (PSD) assessed by magnetic resonance imaging (MRI), which was resolved in a short period. The other patient presented with a marked remission of altered areas compared with the post-operative scans as assessed by MRI. Such aspects are not commonly observed in patients only treated with conventional modalities. This observation might highlight the potential effect of CBD to increase PSD or improve chemoradiation responses that impact survival. Further investigation with more patients and critical molecular analyses should be performed.

The Korean Society for Neuro-Oncology (KSNO) Guideline for WHO Grade II Cerebral Gliomas in Adults: Version 2019.01

BACKGROUND

There was no practical guideline for the management of patients with central nervous system tumor in Korea for many years. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, has developed the guideline for glioblastoma. Subsequently, the KSNO guideline for World Health Organization (WHO) grade II cerebral glioma in adults is established.

METHODS

The Working Group was composed of 35 multidisciplinary medical experts in Korea. References were identified by searching PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL databases using specific and sensitive keywords as well as combinations of keywords regarding diffuse astrocytoma and oligodendroglioma of brain in adults.

RESULTS

Whenever radiological feature suggests lower grade glioma, the maximal safe resection if feasible is recommended globally. After molecular and histological examinations, patients with diffuse astrocytoma, isocitrate dehydrogenase (IDH)-wildtype without molecular feature of glioblastoma should be primarily treated by standard brain radiotherapy and adjuvant temozolomide chemotherapy (Level III) while those with molecular feature of glioblastoma should be treated following the protocol for glioblastomas. In terms of patients with diffuse astrocytoma, IDH-mutant and oligodendroglioma (IDH-mutant and 1p19q codeletion), standard brain radiotherapy and adjuvant PCV (procarbazine+lomustine+vincristine) combination chemotherapy should be considered primarily for the high-risk group while observation with regular follow up should be considered for the low-risk group.

CONCLUSION

The KSNO's guideline recommends that WHO grade II gliomas should be treated by maximal safe resection, if feasible, followed by radiotherapy and/or chemotherapy according to molecular and histological features of tumors and clinical characteristics of patients.

Multidisciplinary Treatment of Pediatric Low-Grade Glioma: Experience of Children Cancer Hospital of Egypt; 2007-2012

Background: Pediatric gliomas comprise a clinically, histologically, and molecularly heterogeneous group of central nervous system tumors. The survival of children with gliomas influenced by histologic subtype, age, and extent of resection. Tumor grade emerged as the most determinant of survival except in the young age groups. The aim of this study was to evaluate the role of multidisciplinary therapeutic approach including surgery and chemotherapy, and their impact on the outcome in pediatric patients with low-grade glioma (LGG). Procedure: Study patients were prospectively enrolled onto the study. All patients were below 18-year-old, diagnosed as LGG between July 2007 and June 2012. Upfront surgical resection was attempted in all tumors other than optic pathway sites. Systemic chemotherapy was given according to CCG-A9952 protocol. Results: Total/near-total resection in 105/227 (46.3%) without adjuvant treatment, while 49/227 patients (21.5%) underwent subtotal tumor resection followed by chemotherapy for big residual (n = 26). Follow-up only was indicated for asymptomatic/small residual (n = 23). The radiological diagnosis was set in 18/227 (7.9%) patients; 13/18 had optic pathway glioma. The 3-year overall survival (OS) was 87.3% versus 65.5% event free survival (EFS) for the whole study patients with a follow-up period of 1–5 years. The OS and EFS for patients who did surgery with no adjuvant treatment (n = 128) were, respectively, 95.2% and 77.3% versus 87.4% and 65.1% for adjuvant chemotherapy group (n = 99); (P = 0.015 and P = 0.016 for OS and EFS, respectively). Conclusion: Pediatric LGGs comprise a wide spectrum of pathological and anatomical entities that carry a high rate of prolonged survival among children and adolescents. Surgical resection is the mainstay of treatment in most of tumors. Combined chemotherapy can be an acceptable alternative when surgery is not safely feasible.

Neurologic and Medical Management of Brain Tumors

Patients with brain tumor encounter a wide spectrum of tumor and treatment-related complications during their disease course. Tumors may serve as seizure substrates, are associated with a hypercoagulable state that results in thromboembolic complications, and may influence mood and cognition. Antitumor and supportive therapies may also have deleterious effects. Herein, we discuss major aspects of supportive care for patients with brain tumors, with attention to benefit and complications derived from the management of seizures, brain edema, venous thromboembolism, fatigue, mood alterations, and cognitive dysfunction.

Procarbazine, lomustine and vincristine toxicity in low-grade gliomas

Background

Procarbazine, lomustine, and vincristine (pcv) significantly improve survival outcomes in lgg (low-grade gliomas). Administration of pcv to lgg patients increased tremendously over the past years as it went from 2 patients per year between 2005 and 2012 to 23 patients in 2015 only in our centre. However, serious hematological and non-hematological adverse events may occur. The purpose of this study was to evaluate the toxicity of pcv and its clinical relevance in our practice.

Methods

We retrospectively reviewed the charts of 57 patients with lgg who received pcv at the Centre hospitalier de l'Université de Montréal between 1 January 2005 and 27 July 2016.

Results

Procarbazine, lomustine, and vincristine were associated with severe hematological toxicity as clinically significant grade 3 anemia, neutropenia, and thrombocytopenia occurred in 7%, 10%, and 28% of patients, respectively. Other frequent adverse events such as the increase of liver enzymes, cutaneous rash, neurotoxicity, and vomiting occurred in 65%, 26%, 60%, and 40% of patients, respectively. Patients with prophylactic trimethoprim/sulfamethoxazole had more grade 3 hematological toxicity with pcv, especially anemia (p = 0.040) and thrombocytopenia (p = 0.003) but we found no increase in pcv toxicity in patients on concurrent anticonvulsants. Patients with grade 3 neutropenia had a significantly lower survival (median survival 44.0 months vs. 114.0 months, p = 0.001). Patients who were given pcv at diagnosis had more grade 3 anemia than those who received it at subsequent lines of treatment (p = 0.042).

Conclusion

Procarbazine, lomustine, and vincristine increase survival in lgg but were also associated with major hematologic, hepatic, neurologic, and cutaneous toxicity. Anti-Pneumocystis jiroveci pneumonia (pjp) prophylaxis, but not anticonvulsants, enhances hematologic toxicity.

Chemotherapy for adult low-grade gliomas: clinical outcomes by molecular subtype in a phase II study of adjuvant temozolomide

Background

Optimal adjuvant management of adult low-grade gliomas is controversial. Recently described tumor classification based on molecular subtype has the potential to individualize adjuvant therapy but has not yet been evaluated as part of a prospective trial.

Methods

Patients aged 18 or older with newly diagnosed World Health Organization grade II low-grade gliomas and gross residual disease after surgical resection were enrolled in the study. Patients received monthly cycles of temozolomide for up to 1 year or until disease progression. For patients with available tissue, molecular subtype was assessed based upon 1p/19q codeletion and isocitrate dehydrogenase-1 R132H mutation status. The primary outcome was radiographic response rate; secondary outcomes included progression-free survival (PFS) and overall survival (OS).

Results

One hundred twenty patients were enrolled with median follow-up of 7.5 years. Overall response rate was 6%, with median PFS and OS of 4.2 and 9.7 years, respectively. Molecular subtype was associated with rate of disease progression during treatment (P<.001), PFS (P=.007), and OS (P<.001). Patients with 1p/19q codeletion demonstrated a 0% risk of progression during treatment. In an exploratory analysis, pretreatment lesion volume was associated with both PFS (P<.001) and OS (P<.001).

Conclusions

While our study failed to meet the primary endpoint for objective radiographic response, patients with high-risk low-grade glioma receiving adjuvant temozolomide demonstrated a high rate of radiographic stability and favorable survival outcomes while meaningfully delaying radiotherapy. Patients with 1p/19q codeletion are potential candidates for omission of adjuvant radiotherapy, but further work is needed to directly compare chemotherapy with combined modality therapy.

Procarbazine, Lomustine, and Vincristine (PCV) Regimen for Central Nervous System Tumors

The complexity of cancer chemotherapy requires pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy, and the agents, both commercially available and investigational, used to treat malignant diseases. Questions or suggestions for topics should be addressed to Dominic A. Solimando, Jr, President, Oncology Pharmacy Services, Inc., 4201 Wilson Blvd #110-545, Arlington, VA 22203, e-mail: OncRxSvc@comcast.net; or J. Aubrey Waddell, Professor, University of Tennessee College of Pharmacy; Oncology Pharmacist, Pharmacy Department, Blount Memorial Hospital, 907 E. Lamar Alexander Parkway, Maryville, TN 37804, e-mail: waddfour@charter.net. The information presented in this review is based on published data and clinical expertise and includes information not included in the product labeling. Incorporation of such published data provides a more robust assessment of the drugs and assists pharmacists in evaluation of orders for off-label use of these agents.

Temozolomide low-dose chemotherapy in newly diagnosed low-grade gliomas: activity, safety, and long-term follow-up

PURPOSE

To explore the efficacy and toxicity of an extended schedule of temozolomide (50 mg/mq 1 week on/1 week off) in a population of newly diagnosed low-grade gliomas (LGG).

METHODS

Primary endpoints were progression-free survival (PFS) at 12 and 24 months and response rate evaluated with Response Assessment in Neuro-Oncology Criteria. Secondary endpoints were clinical benefit (reduction of seizures frequency), reduction of steroid, and modifications of Karnofsky Performance Status.

RESULTS

From 2006 to 2009, we enrolled 14 consecutive patients with newly diagnosed LGG: 8 grade II astrocytomas, 2 oligodendroglioma, and 4 oligo-astrocytoma. Temozolomide was administered for 18 cycles (mean) per patient (range 3-24 cycles). In 57.5% (n = 8), we observed stable disease, 28.5% (n = 4) presented a minor response, and 14% (n = 2) showed progression. Five patients presented early progression during the first year of treatment and the study was stopped. A relevant clinical benefit was observed in 85% of patients (seizure control). After 6 years of follow-up, only 4 patients died. Prolonged PFS was associated with 1p-19q codeletion over 1p-19q intact (35 vs 4 months; p<0.04) and IDH1 mutation over IDH1 wild-type (36 vs 6 months; p<0.009).

CONCLUSIONS

The study was interrupted for the high rate of progression observed in the first 14 patients enrolled. However, our results show that an extended low dose of temozolomide presents interesting activity with objective response and clinical benefit, but does not seem to prevent progression in patients presenting unfavorable molecular prognostic factors.

Seizure control as a new metric in assessing efficacy of tumor treatment in low-grade glioma trials

Patients with low-grade glioma frequently have brain tumor-related epilepsy, which is more common than in patients with high-grade glioma. Treatment for tumor-associated epilepsy usually comprises a combination of surgery, anti-epileptic drugs (AEDs), chemotherapy, and radiotherapy. Response to tumor-directed treatment is measured primarily by overall survival and progression-free survival. However, seizure frequency has been observed to respond to tumor-directed treatment with chemotherapy or radiotherapy. A review of the current literature regarding seizure assessment for low-grade glioma patients reveals a heterogeneous manner in which seizure response has been reported. There is a need for a systematic approach to seizure assessment and its influence on health-related quality-of-life outcomes in patients enrolled in low-grade glioma therapeutic trials. In view of the need to have an adjunctive metric of tumor response in these patients, a method of seizure assessment as a metric in brain tumor treatment trials is proposed.

The withdrawal of antiepileptic drugs in patients with low-grade and anaplastic glioma

INTRODUCTION

The withdrawal of antiepileptic drugs (AEDs) in World Health Organization (WHO) grade II-III glioma patients with epilepsy is controversial, as the presence of a symptomatic lesion is often related to an increased risk of seizure relapse. However, some glioma patients may achieve long-term seizure freedom after antitumor treatment, raising questions about the necessity to continue AEDs, particularly when patients experience serious drug side effects. Areas covered: In this review, we show the evidence in the literature from 1990-2016 for AED withdrawal in glioma patients. We put this issue into the context of risk factors for developing seizures in glioma, adverse effects of AEDs, seizure outcome after antitumor treatment, and outcome after AED withdrawal in patients with non-brain tumor related epilepsy. Expert commentary: There is currently scarce evidence of the feasibility of AED withdrawal in glioma patients. AED withdrawal could be considered in patients with grade II-III glioma with a favorable prognosis, who have achieved stable disease and long-term seizure freedom. The potential benefits of AED withdrawal need to be carefully weighed against the presumed risk of seizure recurrence in a shared decision-making process by both the clinical physician and the patient.

Current Management of Adult Diffuse Infiltrative Low Grade Gliomas

Diffuse infiltrative low grade gliomas (LGG) account for approximately 15 % of all gliomas. The prognosis of LGG differs between high-risk and low-risk patients notwithstanding varying definitions of what constitutes a high-risk patient. Maximal safe resection optimally is the initial treatment. Surgery that achieves a large volume resection improves both progression-free and overall survival. Based on results of three randomized clinical trials (RCT), radiotherapy (RT) may be deferred in patients with low-risk LGG (defined as age <40 years and having undergone a complete resection), although combined chemoradiotherapy has never been prospectively evaluated in the low-risk population. The recent RTOG 9802 RCT established a new standard of care in high-risk patients (defined as age >40 years or incomplete resection) by demonstrating a nearly twofold improvement in overall survival with the addition of PCV (procarbazine, CCNU, vincristine) chemotherapy following RT as compared to RT alone. Chemotherapy alone as a treatment of LGG may result in less toxicity than RT; however, this has only been prospectively studied once (EORTC 22033) in high-risk patients. A challenge remains to define when an aggressive treatment improves survival without impacting quality of life (QoL) or neurocognitive function and when an effective treatment can be delayed in order to preserve QoL without impacting survival. Current WHO histopathological classification is poorly predictive of outcome in patients with LGG. The integration of molecular biomarkers with histology will lead to an improved classification that more accurately reflects underlying tumor biology, prognosis, and hopefully best therapy.

Epilepsy and brain tumors

Seizures are common in patients with brain tumors, and epilepsy can significantly impact patient quality of life. Therefore, a thorough understanding of rates and predictors of seizures, and the likelihood of seizure freedom after resection, is critical in the treatment of brain tumors. Among all tumor types, seizures are most common with glioneuronal tumors (70-80%), particularly in patients with frontotemporal or insular lesions. Seizures are also common in individuals with glioma, with the highest rates of epilepsy (60-75%) observed in patients with low-grade gliomas located in superficial cortical or insular regions. Approximately 20-50% of patients with meningioma and 20-35% of those with brain metastases also suffer from seizures. After tumor resection, approximately 60-90% are rendered seizure-free, with most favorable seizure outcomes seen in individuals with glioneuronal tumors. Gross total resection, earlier surgical therapy, and a lack of generalized seizures are common predictors of a favorable seizure outcome. With regard to anticonvulsant medication selection, evidence-based guidelines for the treatment of focal epilepsy should be followed, and individual patient factors should also be considered, including patient age, sex, organ dysfunction, comorbidity, or cotherapy. As concomitant chemotherapy commonly forms an essential part of glioma treatment, enzyme-inducing anticonvulsants should be avoided when possible. Seizure freedom is the ultimate goal in the treatment of brain tumor patients with epilepsy, given the adverse effects of seizures on quality of life.

Low-grade and anaplastic oligodendroglioma

Anaplastic oligodendrogliomas have long attracted interest because of their sensitivity to chemotherapy, in particular in the subset of 1p/19q co-deleted tumors. Recent molecular studies have shown that all 1p/19q co-deleted tumors have IDH mutations and most of them also have TERT mutations. Because of the presence of similar typical genetic alterations in astrocytoma and glioblastoma, the current trend is to diagnose these tumors on the basis of their molecular profile. Further long-term follow-up analysis of both EORTC and RTOG randomized studies on (neo)adjuvant procarbazine, lomustine, vincristine (PCV) chemotherapy have shown that adjuvant chemotherapy indeed improves outcome, and this is now standard of care. It is also equally clear that benefit to PCV chemotherapy is not limited to the 1p/19q co-deleted cases; potential other predictive factors are IDH mutations and MGMT promoter methylation. Moreover, a recent RTOG study on low-grade glioma also noted an improved outcome after adjuvant PCV chemotherapy, thus making (PCV) chemotherapy now standard of care for all 1p/19q co-deleted tumors regardless of grade. It remains unclear whether temozolomide provides the same survival benefit, as no data from well-designed clinical trials on adjuvant temozolomide in this tumor type are available. Another question that remains is whether one can safely leave out radiotherapy as part of initial treatment to avoid cognitive side-effects of radiotherapy. The current data suggest that delaying radiotherapy and treatment with chemotherapy only may be detrimental for overall survival.

Management of patients with recurrence of diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

TARGET POPULATION

These recommendations apply to adult patients with recurrent low-grade glioma (LGG) with initial pathologic diagnosis of a WHO grade II infiltrative glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

PATHOLOGY AT RECURRENCE

QUESTION

Do pathologic and molecular characteristics predict outcome/malignant transformation at recurrence?

RECOMMENDATIONS

IDH STATUS AND RECURRENCE: (Level III) IDH mutation status should be determined as LGGs with IDH mutations have a shortened time to recurrence. It is unclear whether knowledge of IDH mutation status provides benefit in predicting time to progression or overall survival. TP53 STATUS AND RECURRENCE: (Level III) TP53 mutations occur early in LGG pathogenesis, remain stable, and are not recommended as a marker of predisposition to malignant transformation at recurrence or other measures of prognosis. MGMT STATUS AND RECURRENCE: (Level III) Assessment of MGMT status is recommended as an adjunct to assessing prognosis as LGGs with MGMT promoter methylation are associated with shorter PFS (in the absence of TMZ) and longer post-recurrence survival (in the presence of TMZ), ultimately producing similar overall survival to LGGs without MGMT methylation. The available retrospective reports are conflicting and comparisons between reports are limited CDK2NA STATUS AND RECURRENCE: (Level III) Assessment of CDK2NA status is recommended when possible as the loss of expression of the CDK2NA via either methylation or loss of chromosome 9p is associated with malignant progression of LGGs. PROLIFERATIVE INDEX AND RECURRENCE: (Level III) It is recommended that proliferative indices (MIB-1 or BUdR) be measured in LGGs as higher proliferation indices are associated with increased likelihood of recurrence and shorter progression free and overall survival. 1P/19Q STATUS AND RECURRENCE: There is insufficient evidence to make any recommendations.

CHEMOTHERAPY AT RECURRENCE

QUESTION

What role does chemotherapy have in LGG recurrence?

RECOMMENDATIONS

TEMOZOLOMIDE AND RECURRENCE: (Level III) Temozolomide is recommended in the therapy of recurrent LGG as it may improve clinical symptoms. Oligodendrogliomas and tumors with 1p/19q co-deletion may derive the most benefit. PCV AND RECURRENCE: (Level III) PCV is recommended in the therapy of LGG at recurrence as it may improve clinical symptoms with the strongest evidence being for oligodendrogliomas. CARBOPLATIN AND RECURRENCE : (Level III) Carboplatin is not recommended as there is no significant benefit from carboplatin as single agent therapy for recurrent LGGs. OTHER TREATMENTS (NITROSUREAS, HYDROXYUREA/IMANITIB, IRINOTECAN, PACLITAXEL) AND RECURRENCE: There is insufficient evidence to make any recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess these chemotherapeutic agents.

RADIATION AT RECURRENCE

QUESTION

What role does radiation have in LGG recurrence?

RECOMMENDATIONS

RADIATION AT RECURRENCE WITH NO PREVIOUS IRRADIATION: (Level III) Radiation is recommended at recurrence if there was no previous radiation treatment. RE-IRRADIATION AT RECURRENCE: (Level III) It is recommended that re-irradiation be considered in the setting of LGG recurrence as it may provide benefit in disease control.

SURGERY AT RECURRENCE

There is insufficient evidence to make any specific recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess the role of surgery at recurrence.

Seizure reduction is a prognostic marker in low-grade glioma patients treated with temozolomide

We aimed to analyze the value of seizure reduction and radiological response as prognostic markers of survival in patients with low-grade glioma (LGG) treated with temozolomide (TMZ) chemotherapy. We retrospectively reviewed adult patients with a progressive LGG and uncontrolled epilepsy in two hospitals (VUmc Amsterdam; MCH The Hague), who received chemotherapy with TMZ between 2002 and 2014. End points were a ≥50 % seizure reduction and MRI response 6, 12 and 18 months (mo) after the start of TMZ, and their relation with progression-free survival (PFS) and overall survival (OS). We identified 53 patients who met the inclusion criteria. Seizure reduction was an independent prognostic factor for both PFS (HR 0.38; 95 % CI 0.19–0.73; p = 0.004) and OS (HR 0.39; 95 % CI 0.18–0.85; p = 0.018) after 6mo, adjusting for age and histopathological diagnosis, as well as after 12 and 18mo. Patients with an objective radiological response showed a better OS (median 87.5mo; 95 % CI 62.0–112.9) than patients without a response (median 34.4mo; 95 % CI 26.1–42.6; p = 0.046) after 12mo. However, after 6 and 18mo OS was similar in patients with and without a response on MRI. Seizure reduction is an early and consistent prognostic marker for survival after treatment with TMZ, that seems to precede the radiological response. Therefore, seizure reduction may serve as a surrogate marker for tumor response.

Clinical management of grade III oligodendroglioma

Oligodendrogliomas represent the third most common type of glioma, comprising 4%-15% of all gliomas and can be classified by degree of malignancy into grade II and grade III, according to WHO classification. Only 30% of oligodendroglial tumors have anaplastic characteristics. Anaplastic oligodendroglioma (AO) is often localized as a single lesion in the white matter and in the cortex, rarely in brainstem or spinal cord. The management of AO is deeply changed in the recent years. Maximal safe surgical resection followed by radiotherapy (RT) was considered as the standard of care since paramount findings regarding molecular aspects, in particular co-deletion of the short arm of chromosome 1 and the long arm of chromosome 19, revealed that these subsets of AO, benefit in terms of overall survival (OS) and progression-free survival (PFS), from the addition of chemotherapy to RT. Allelic losses of chromosomes 1p and 19q occur in 50%-70% of both low-grade and anaplastic tumors, representing a strong prognostic factor and a powerful predictor of prolonged survival. Several other molecular markers have potential clinical significance as IDH1 mutations, confirming the strong prognostic role for OS. Malignant brain tumors negatively impacts on patients' quality of life. Seizures, visual impairment, headache, and cognitive disorders can be present. Moreover, chemotherapy and RT have important side effects. For these reasons, "health-related quality of life" is becoming a topic of growing interest, investigating on physical, mental, emotional, and social well-being. Understanding the impact of medical treatment on health-related quality of life will probably have a growing effect both on health care strategies and on patients.

Epilepsy in patients with primary brain tumors: The impact on mood, cognition, and HRQOL

BACKGROUND

A primary brain tumor (PBT) is often a fatal disease of the nervous system and has a serious impact on health-related quality of life (HRQOL). Presence of epilepsy and adverse reactions from tumor and epilepsy treatments may cause additional decline in HRQOL.

OBJECTIVES

We aimed to study the impact of epileptic seizures on cognition, mood, and HRQOL in patients with brain tumor-related epilepsy.

MATERIALS AND METHOD

Patients were grouped on an ordinal scale according to epilepsy burden from none to severe based on the presence of epileptic seizures and seizure frequency: L1, no epilepsy; L2, with epilepsy, seizure-free in the last 6 months with antiepileptic drugs; and L3, with epilepsy, at least one seizure in the last 6 months with AEDs. Health-related quality of life was measured by Functional Assessment of Cancer Therapy-Brain (FACT-Br) and Quality of Life in Epilepsy-31 (QOLIE-31) tools, cognition by the Montreal Cognitive Assessment (MoCA) tool and Frontal Assessment Battery (FAB), mood by the Hospital Anxiety and Depression Scale (HADS), activities of daily living (ADLs) by the Barthel Index (BI), and performance status by the Karnofsky Performance Status (KPS) scale in patients with primary brain tumors at least one month following neurosurgery with or without radiotherapy and chemotherapy.

RESULTS

Eighty-one patients with a diagnosis of primary brain tumors were recruited. Sixty-eight percent of patients were diagnosed with primary brain tumor-related epilepsy, 50.61% patients had cognitive impairment, 33% had abnormal scores in the anxiety scale, and 34% had abnormal scores in the depression scale. There were no statistically significant differences in these scores among L1, L2, and L3 groups. There were statistically significant differences in duration of disease and KPS and BI scores between L1 and L3 groups. The L3 group has significantly longer duration of disease and scored low in both the BI and KPS scale when compared to the L1 group. All patients with primary brain tumors scored significantly low in FACT-Br 'physical well-being' (PWB) and 'emotional well-being' (EWB) and high in 'social well-being' (SWB) when compared to healthy controls. When scores of each group were individually compared to healthy controls, the L3 group showed the lowest scores in PWB, EWB, and 'functional well-being'. In SWB, L1 and L2 groups showed statistically significantly high scores when compared to normative data. The QOLIE-31 applied to groups with epilepsy showed statistically significantly lower scores in the L3 group when compared to the L2 group in 'cognitive' and 'social functioning' domains. On multivariate analysis, both poor performance status and frequency of seizures were found to be independent risk factors for poor HRQOL when FACT-Br mean scores were compared. Level of seizures was found to be an independent risk factor for poor HRQOL when QOLIE-31 scores were compared between L2 and L3 groups.

DISCUSSION

Presence of brain tumors could be attributed to cognitive impairment irrespective of the presence of epilepsy in our cohort. High seizure burden is an independent risk factor for poor HRQOL in patients with primary brain tumors. The QOLIE-31 is a more sensitive tool than the FACT-Br because of the presence of a seizure-related questionnaire.

Anaplastic glioma: current treatment and management

Anaplastic glioma (AG) is divided into three morphology-based groups (anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic oligoastrocytoma) as well as three molecular groups (glioma-CpG island methylation phenotype [G-CIMP] negative, G-CIMP positive non-1p19q codeleted tumors and G-CIMP positive codeleted tumors). The RTOG 9402 and EORTC 26951 trials established radiotherapy plus (procarbazine, lomustine, vincristine) chemotherapy as the standard of care in 1p/19q codeleted AG. Uni- or non-codeleted AG are currently best treated with radiotherapy only or alkylator-based chemotherapy only as determined by the NOA-04 trial. Maturation of NOA-04 and results of the currently accruing studies, CODEL (for codeleted AG) and CATNON (for uni or non-codeleted AG), will likely refine current up-front treatment recommendations for AG.

Seizure outcome after radiotherapy and chemotherapy in low-grade glioma patients: a systematic review

There is growing evidence that antitumor treatment contributes to better seizure control in low-grade glioma patients. We performed a systematic review of the current literature on seizure outcome after radiotherapy and chemotherapy and evaluated the association between seizure outcome and radiological response. Twenty-four studies were available, of which 10 described seizure outcome after radiotherapy and 14 after chemotherapy. All studies demonstrated improvements in seizure outcome after antitumor treatment. Eight studies reporting on imaging response in relation to seizure outcome showed a seizure reduction in a substantial part of patients with stable disease on MRI. Seizure reduction may therefore be the only noticeable effect of antitumor treatment. Our findings demonstrate the clinical relevance of monitoring seizure outcome after radiotherapy and chemotherapy, as well as the potential role of seizure reduction as a complementary marker of tumor response in low-grade glioma patients.

Indications for Treatment: Is Observation or Chemotherapy Alone a Reasonable Approach in the Management of Low-Grade Gliomas?

The treatment of newly diagnosed low-grade gliomas remains controversial. Recently published results from the long-term follow-up of Radiation Therapy Oncology Group (RTOG) trial 9802 demonstrated medically meaningful and statistically significant survival prolongation by adding chemotherapy with procarbazine, lomustine (CCNU), and vincristine after radiotherapy (RT) vs RT alone for "high"-risk patients (median 13.3 vs 7.8 years, hazard ratio = 0.59, P = 0.03). However, in the 17 years since that trial was launched, there have been advances in the understanding of low-grade gliomas biology and patient heterogeneity, an increased recognition of late neurocognitive injury from early RT, and the emergence of temozolomide as an alternative chemotherapy to procarbazine, lomustine (CCNU), and vincristine. These and other changes in the treatment landscape make the applicability of results from RTOG 9802 to all patients less clear. Moreover, in some patients, especially those at the lowest risk for early disease progression, deferred RT in favor of active surveillance or chemotherapy alone may remain a reasonable treatment approach.

Radiation Therapy Oncology Group 9802: Controversy or Consensus in the Treatment of Newly Diagnosed Low-Grade Glioma?

Treatment of newly diagnosed or suspected low-grade glioma (LGG) is one of the most controversial areas in neuro-oncology. The heterogeneity of these tumors, concern regarding morbidity of treatment, and absence of proven overall survival benefit from any known treatment have resulted in a lack of consensus regarding the timing and extent of surgery, timing of radiotherapy (RT), and role of chemotherapy. The long-term results of Radiation Therapy Oncology Group (RTOG) 9802, a phase III randomized trial comparing RT alone with RT and 6 cycles of adjuvant procarbazine, CCNU, vincristine (PCV), demonstrated an unprecedented 5.5-year improvement in median overall survival with the addition of PCV chemotherapy in high-risk patients with LGG. These results are practice changing and define a new standard of care for these patients. However, in the intervening decade since the trial was completed, novel molecular markers as well as newer chemotherapy agents such as temozolomide have been developed, which make these results difficult to incorporate into clinical practice. This review summarizes the evidence for and against the role of upfront RT and PCV in newly diagnosed patients with LGG.

Pharmacologic therapies for malignant glioma: a guide for clinicians

This review covers the medical options for malignant gliomas based on the results of recent clinical trials and updated information on molecular markers of prognostic and predictive value. In addition to alkylating agents, the antiangiogenic drug bevacizumab is increasingly used, particularly in cases of recurrence. Supportive care, including antiedema agents, antiepileptic drugs and anticoagulants, represent complementary treatment approaches of the utmost clinical importance.

Treatment of large low-grade oligodendroglial tumors with upfront procarbazine, lomustine, and vincristine chemotherapy with long follow-up: a retrospective cohort study with growth kinetics

We treated patients with newly diagnosed and large low-grade oligodendroglial tumors with upfront procarbazine, CCNU and vincristine (PCV) in order to delay radiotherapy. Patients were treated with PCV for a maximum of 6 cycles. The response to treatment was defined according to the RANO criteria; in addition change over time of mean tumor diameters (growth kinetics) was calculated. Thirty-two patients were treated between 1998 and 2006, 18 of which were diagnosed with 1p/19q co-deleted tumors. Median follow-up duration was 8 years (range 0.5-13 years). The median overall survival (mOS) was 120 months and the median progression-free survival (mPFS) was 46 months. Growth kinetics showed an ongoing decrease of the mean tumor diameter after completion of chemotherapy, during a median time of 35 months, but an increase of the mean tumor diameter did not herald progression as detected by RANO criteria. 1p/19q co-deletion was associated with a significant increase in OS (mOS 83 months versus not reached for codeleted tumors; p = 0.003)) and PFS (mPFS 35 months versus 67 months for codeleted tumors; p = 0.024). Patients with combined 1p/19q loss had a 10 year PFS of 34 % and the radiotherapy in these patients was postponed for a median period of more than 6 years. This long-term follow-up study indicates that upfront PCV chemotherapy is associated with long PFS and OS and delays radiotherapy for a considerable period of time in patients with low-grade oligodendroglial tumors, in particular with combined 1p/19q loss.

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.

Temozolomide salvage chemotherapy for recurrent anaplastic oligodendroglioma and oligo-astrocytoma

OBJECTIVE

To evaluate the efficacy of temozolomide (TMZ) chemotherapy for recurrent anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA).

METHODS

A multi-center retrospective trial enrolled seventy-two patients with histologically proven AO/AOA who underwent TMZ chemotherapy for their recurrent tumors from 2006 to 2010. TMZ was administered orally (150 to 200 mg/m(2)/day) for 5 days per 28 days until unacceptable toxicity occurred or tumor progression was observed.

RESULTS

TMZ chemotherapy cycles administered was median 5.3 (range, 1-41). The objective response rate was 24% including 8 cases (11%) of complete response and another 23 patients (32%) were remained as stable disease. Severe side effects (≥grade 3) occurred only in 9 patients (13%). Progression-free survival (PFS) of all patients was a median 8.0 months (95% confidence interval, 6.0-10.0). The time to recurrence of a year or after was a favorable prognostic factor for PFS (p<0.05). Overall survival (OS) was apparently differed by the patient's histology, as AOA patients survived a median OS of 18.0 months while AO patients did not reach median OS at median follow-up of 11.5 months (range 2.7-65 months). Good performance status of Eastern Cooperative Oncology Group 0 and 1 showed prolonged OS (p<0.01).

CONCLUSION

For recurrent AO/AOA after surgery followed by radiation therapy, TMZ could be recommended as a salvage therapy at the estimated efficacy equal to procarbazine, lomustine, and vincristine (PCV) chemotherapy at first relapse. For patients previously treated with PCV, TMZ is a favorable therapeutic option as 2nd line salvage chemotherapy with an acceptable toxicity rate.

Radiotherapy in low-grade glioma adult patients: a retrospective survival and neurocognitive toxicity analysis

PURPOSE

The treatment of low-grade glioma is still debated. Surgery is the first-line approach, and the correct timing of radiation therapy has not yet been defined since "early" radiation therapy improves relapse-free survival but not overall survival. Since a longer progression-free survival is desirable, the main issue related to radiotherapy is the incidence of late neurocognitive toxicity.

MATERIALS AND METHODS

Ninety-five patients with low-grade glioma were consecutively treated with early (within 3 months) or late (at disease progression) post-surgical radiation therapy. Clinical and therapeutic factors were entered into the analysis overall (OS) and progression-free (PFS) survival, and the distribution in two accrual periods identified based on the evolution of imaging procedures and radiotherapy techniques were compared. For 6/18 long survivors (LS) without evidence of disease, neurocognitive evaluation was obtained and the dose to the hippocampus region was retrospectively calculated.

RESULTS

Univariate analysis of OS showed a statistically significant advantage for grade 1 and oligodendroglioma histology, better performance status [Karnofsky index (KI)], age <40 years, radical surgery, no steroid treatment; PFS was significantly related with younger age, better KI and "early" radiotherapy. Multivariate analysis of OS confirmed the significance of all variables except surgery; for PFS, only "early" radiotherapy and better KI retained significance. Memory impairment was evident in 4/6 of the LS tested; quality of life was good and executive functions were normal.

CONCLUSION

Radiotherapy remains an essential component in the treatment of low-grade glioma. Prospective studies are needed to evaluate the relative contributions of the disease itself and of surgery, radiation and chemotherapy to long-term neurocognitive damage.

Effects of the selective MPS1 inhibitor MPS1-IN-3 on glioblastoma sensitivity to antimitotic drugs

BACKGROUND

Glioblastomas exhibit a high level of chemotherapeutic resistance, including to the antimitotic agents vincristine and taxol. During the mitotic agent-induced arrest, glioblastoma cells are able to perform damage-control and self-repair to continue proliferation. Monopolar spindle 1 (MPS1/TTK) is a checkpoint kinase and a gatekeeper of the mitotic arrest.

METHODS

We used glioblastoma cells to determine the expression of MPS1 and to determine the effects of MPS1 inhibition on mitotic errors and cell viability in combination with vincristine and taxol. The effect of MPS1 inhibition was assessed in different orthotopic glioblastoma mouse models (n = 3-7 mice/group). MPS1 expression levels were examined in relation to patient survival.

RESULTS

Using publicly available gene expression data, we determined that MPS1 overexpression corresponds positively with tumor grade and negatively with patient survival (two-sided t test, P < .001). Patients with high MPS1 expression (n = 203) had a median and mean survival of 487 and 913 days (95% confidence intervals [CI] = 751 to 1075), respectively, and a 2-year survival rate of 35%, whereas patients with intermediate MPS1 expression (n = 140) had a median and mean survival of 858 and 1183 days (95% CI = 1177 to 1189), respectively, and a 2-year survival rate of 56%. We demonstrate that MPS1 inhibition by RNAi results in sensitization to antimitotic agents. We developed a selective small-molecule inhibitor of MPS1, MPS1-IN-3, which caused mitotic aberrancies in glioblastoma cells and, in combination with vincristine, induced mitotic checkpoint override, increased aneuploidy, and augmented cell death. MPS1-IN-3 sensitizes glioblastoma cells to vincristine in orthotopic mouse models (two-sided log-rank test, P < .01), resulting in prolonged survival without toxicity.

CONCLUSIONS

Our results collectively demonstrate that MPS1, a putative therapeutic target in glioblastoma, can be selectively inhibited by MPS1-IN-3 sensitizing glioblastoma cells to antimitotic drugs.

Seizure control following radiotherapy in patients with diffuse gliomas: a retrospective study

BACKGROUND

Little information is available regarding the effect of conventional radiotherapy on glioma-related seizures.

METHODS

In this retrospective study, we analyzed the seizure response and outcome following conventional radiotherapy in a cohort of 43 patients with glioma (33 grade II, 10 grade III) and medically intractable epilepsy.

RESULTS

At 3 months after radiotherapy, seizure reduction was significant (≥ 50% reduction of frequency compared with baseline) in 31/43 patients (72%) of the whole series and in 25/33 patients (76%) with grade II gliomas, whereas at 12 months seizure reduction was significant in 26/34 (76%) and in 19/25 (76%) patients, respectively. Seizure reduction was observed more often among patients displaying an objective tumor response on MRI, but patients with no change on MRI also had a significant seizure reduction. Seizure freedom (Engel class I) was achieved at 12 months in 32% of all patients and in 38% of patients with grade II tumors. Timing of radiotherapy and duration of seizures prior to radiotherapy were significantly associated with seizure reduction.

CONCLUSIONS

This study showed that a high proportion of patients with medically intractable epilepsy from diffuse gliomas derive a significant and durable benefit from radiotherapy in terms of epilepsy control and that this positive effect is not strictly associated with tumor shrinkage as shown on MRI. Radiotherapy at tumor progression seems as effective as early radiotherapy after surgery. Prospective studies must confirm and better characterize the response to radiotherapy.

Seizures in low-grade gliomas: natural history, pathogenesis, and outcome after treatments

Seizures represent a common symptom in low-grade gliomas; when uncontrolled, they significantly contribute to patient morbidity and negatively impact quality of life. Tumor location and histology influence the risk for epilepsy. The pathogenesis of tumor-related epilepsy is multifactorial and may differ among tumor histologies (glioneuronal tumors vs diffuse grade II gliomas). Gross total resection is the strongest predictor of seizure freedom in addition to clinical factors, such as preoperative seizure duration, type, and control with antiepileptic drugs (AEDs). Epilepsy surgery may improve seizure control. Radiotherapy and chemotherapy with alkylating agents (procarbazine + CCNU+ vincristine, temozolomide) are effective in reducing the frequency of seizures in patients with pharmacoresistant epilepsy. Newer AEDs (levetiracetam, topiramate, lacosamide) seem to be better tolerated than the old AEDs (phenobarbital, phenytoin, carbamazepine), but there is lack of evidence regarding their superiority in terms of efficacy.

Chemotherapy in low-grade gliomas

PURPOSE OF REVIEW

This review summarizes the recent studies in adults' diffuse low-grade gliomas (LGGs) chemotherapy, including response assessment and potential predictive biomarkers of chemosensitivity.

RECENT FINDINGS

Recent studies have confirmed that chemotherapy is an interesting treatment option in LGGs. About 25-50% of LGGs achieve radiological responses with temozolomide or a procarbazine-CCNU-vincristine (PCV) regimen. Clinical and quality-of-life improvements are commonly observed with more than half of the patients with epilepsy, demonstrating a significant reduction of seizure frequency. Dynamic volumetric studies have provided a better description of LGGs evolution after chemotherapy. They have shown that an ongoing volume decrease can be observed many months after chemotherapy discontinuation, particularly after PCV, raising the question of how and for how long should LGGs be treated. New response criteria have been defined by the Response Assessment in Neuro-Oncology group. In addition to 1p/19q codeletion and MGMT promoter methylation, IDH1 mutation might also be a potential predictive biomarker of chemosensitivity.

SUMMARY

It has now been widely accepted that chemotherapy is an interesting treatment option in LGGs. However, several questions remain unanswered regarding its optimal use. Ongoing phase III studies will allow a better delineation of the role of chemotherapy in LGGs and will also help to better determine the potential predictive value of a 1p/19q codeletion, a MGMT promoter methylation and an IDH1 mutation.

Combination of neoadjuvant chemotherapy followed by surgical resection as a new strategy for WHO grade II gliomas: a study of cognitive status and quality of life

Diffuse WHO grade II (GIIG) may be unresectable when involving critical structures. To assess the feasibility and functional tolerance (cognition and quality of life) of an original therapeutic strategy combining neoadjuvant chemotherapy followed by surgical resection for initially inoperable GIIG. Ten patients underwent Temozolomide for unresectable GIIG, as initial treatment or at recurrence after previous partial resection, due to invasion of eloquent areas or bi-hemispheric diffusion preventing a total/subtotal removal. Functional outcome after both treatments was assessed, with evaluation of seven cognitive domains. Chemotherapy induced tumor shrinkage (median volume decrease 38.9%) in ipsilateral functional areas in six patients and in the contralateral hemisphere in four. Only four patients had a 1p19q codeletion. The tumor shrinkage made possible the resection (mean extent of resection 93.3%, 9 total or subtotal removals) of initially inoperable tumors. Postoperatively, three patients had no deficits, while verbal episodic memory and executive functions were slightly impaired in seven patients. However, global quality of life was roughly preserved on the EORTC QLQ C30 + BN 20 (median score: 66.7%). Role functioning score was relatively reduced (median score: 66.7%) whereas KPS was preserved (median score: 90, range 80-100). Seven patients became seizure-free while three improved. This combined treatment is feasible, efficient (surgery made possible by neoadjuvant chemotherapy) and well-tolerated (preservation of quality of life, no serious cognitive disturbances). Cognitive deficits seem mostly related to tumor location. Because KPS is not reliable enough, a detailed neuropsychological assessment should be systematically performed in GIIG.

Recurrent high-grade glioma

OPINION STATEMENT

Opinions vary on the best treatment options for recurrent high-grade glioma. Some argue that bevacizumab should become standard of care for patients with recurrent glioblastoma, especially in light of recent FDA approval for this indication. However, this opinion is not uniformly accepted. Age, performance status, histology, tumor size and location, O6-methylguanine-DNA methyltransferase (MGMT) methylation status for glioblastoma, 1p/19q status for oligodendroglial tumors, and the number and types of prior therapies are important considerations. In addition, recurrent disease must be distinguished from "pseudoprogression" due to treatment effects. Enrollment in a clinical trial is the optimal choice for most patients with recurrent high-grade glioma after failure of radiation therapy and temozolomide. For patients who are ineligible or do not have access to clinical trials, then either bevacizumab monotherapy or bevacizumab in combination with a second agent such as irinotecan is recommended. Involved-field external beam radiation should be considered for patients with anaplastic gliomas who have not received radiation. For patients with anaplastic astrocytoma who progress after radiotherapy, temozolomide may be used. For patients with anaplastic oligodendroglioma who progress after radiotherapy, PCV chemotherapy and temozolomide are options. Oligodendroglial tumors with 1p/19q deletions are more likely to respond to treatment. In the past, carmustine was commonly used to treat recurrent high-grade glioma, but the utility of carmustine in the modern era is unknown because most studies were performed prior to the widespread use of temozolomide. High-precision re-irradiation such as stereotactic radiosurgery is another option in high-grade glioma, especially for patients with poor bone marrow reserve or inability to tolerate chemotherapy, but there is a paucity of studies with adequate controls. Surgery may be useful as adjuvant treatment for patients with symptoms due to mass effect or for patients requiring definitive histopathology, but it generally should be combined with another treatment modality. Emerging therapies, including dose-intense temozolomide regimens, targeted molecular inhibitors, other antiangiogenic therapies, viral gene therapies, immunotherapies, and convection-enhanced delivery of targeted immunotoxins, are still under investigation.

Anaplastic oligodendroglioma

Although uncommon, anaplastic oligodendrogliomas (AODs) are important to recognize, as they have unique molecular, histologic, and clinical features. Patients with new seizures or new focal neurologic deficits should be referred for brain MRI with contrast. If the MRI suggests a malignant glioma, maximal feasible tumor resection is advised for accurate diagnosis and for relief of tumor-related neurologic symptoms. Radiation therapy (XRT) is the most commonly prescribed postsurgical therapy for patients with AODs. The role and timing of adjuvant chemotherapy are less clear. Tumor responses to PCV (the combination of procarbazine, lomustine, and vincristine) and to temozolomide have been documented in patients with AODs. However, two prospective phase 3 trials in patients with newly diagnosed AOD have shown no difference in overall survival when PCV is added to XRT. Ongoing trials investigating the benefit of temozolomide plus XRT in patients with newly diagnosed AOD will inform about the value of this common practice. The recognition that 1p19q codeletion is a marker of oligodendroglial differentiation and the subsequent prospective confirmation of this marker's importance in predicting better prognosis have been critical discoveries. Tumors with intermediate oligodendroglial features or mixed astrocytic features should be referred for 1p19q assessment. Identification of 1p19q status is also required in clinical trials for patients with AOD, given the association of 1p19q codeletion with improved response to therapies and overall prognosis. There are not yet sufficient data to guide individual treatment planning based on 1p19q status, but several planned and ongoing trials will address this issue. Unfortunately, AOD remains a terminal brain cancer even with maximal therapies. As more therapeutic options become available and the full significance of molecular markers is understood, 1p19q and other markers are expected to help guide optimal antitumor therapies, and it is hoped that survival and function will improve for all patients with AOD.

Assessment of therapeutic response and treatment planning for brain tumors using metabolic and physiological MRI

MRI is routinely used for diagnosis, treatment planning and assessment of response to therapy for patients with glioma. Gliomas are spatially heterogeneous and infiltrative lesions that are quite variable in terms of their response to therapy. Patients classified as having low-grade histology have a median overall survival of 7 years or more, but need to be monitored carefully to make sure that their tumor does not upgrade to a more malignant phenotype. Patients with the most aggressive grade IV histology have a median overall survival of 12-15 months and often undergo multiple surgeries and adjuvant therapies in an attempt to control their disease. Despite improvements in the spatial resolution and sensitivity of anatomic images, there remain considerable ambiguities in the interpretation of changes in the size of the gadolinium-enhancing lesion on T(1) -weighted images as a measure of treatment response, and in differentiating between treatment effects and infiltrating tumor within the larger T(2) lesion. The planning of focal therapies, such as surgery, radiation and targeted drug delivery, as well as a more reliable assessment of the response to therapy, would benefit considerably from the integration of metabolic and physiological imaging techniques into routine clinical MR examinations. Advanced methods that have been shown to provide valuable data for patients with glioma are diffusion, perfusion and spectroscopic imaging. Multiparametric examinations that include the acquisition of such data are able to assess tumor cellularity, hypoxia, disruption of normal tissue architecture, changes in vascular density and vessel permeability, in addition to the standard measures of changes in the volume of enhancing and nonenhancing anatomic lesions. This is particularly critical for the interpretation of the results of Phase I and Phase II clinical trials of novel therapies, which are increasingly including agents that are designed to have anti-angiogenic and anti-proliferative properties as opposed to having a direct effect on tumor cell viability.