Correlation of enzyme-inducing anticonvulsant use with outcome of patients with glioblastoma

Relevant pharmacological interactions between alkylating agents and antiepileptic drugs: Preclinical and clinical data

Seizures are relatively common in cancer patients, and co-administration of chemotherapeutic and antiepileptic drugs (AEDs) is highly probable and necessary in many cases. Nonetheless, clinically relevant interactions between chemotherapeutic drugs and AEDs are rarely summarized and pharmacologically described. These interactions can cause insufficient tumor and seizure control or lead to unforeseen toxicity. This review focused on pharmacokinetic and pharmacodynamic interactions between alkylating agents and AEDs, helping readers to make a rational choice of treatment optimization, and thus improving patients' quality of life. As an example, phenobarbital, phenytoin, and carbamazepine, by increasing the hepatic metabolism of cyclophosphamide, ifosfamide and busulfan, yield smaller peak concentrations and a reduced area under the plasma concentration-time curve (AUC) of the prodrugs; alongside, the maximum concentration and AUC of their active products were increased with the possible onset of severe adverse drug reactions. On the other side, valproic acid, acting as histone deacetylase inhibitor, showed synergistic effects with temozolomide when tested in glioblastoma. The present review is aimed at providing evidence that may offer useful suggestions for rational pharmacological strategies in patients with seizures symptoms undertaking alkylating agents. Firstly, clinicians should avoid the use of enzyme-inducing AEDs in combination with alkylating agents and prefer the use of AEDs, such as levetiracetam, that have a low or no impact on hepatic metabolism. Secondly, a careful therapeutic drug monitoring of both alkylating agents and AEDs (and their active metabolites) is necessary to maintain therapeutic ranges and to avoid serious adverse reactions.

Effect of Levetiracetam Use Duration on Overall Survival of Isocitrate Dehydrogenase Wildtype Glioblastoma in Adults: An Observational Study

OBJECTIVES

The association between Levetiracetam and survival of Isocitrate Dehydrogenase (IDH) wildtype glioblastomas is controversial. We investigated whether the duration of Levetiracetam use during the standard chemoradiation protocol impacts overall survival of IDH-wildtype glioblastoma patients.

METHODS

Observational single-institution cohort study (2010-2018). Inclusion criteria were: 1) patients ≥18 years old; 2) newly diagnosed supratentorial tumor; 3) histomolecular diagnosis of IDH-wildtype glioblastoma; 4) standard chemoradiation protocol. To assess the survival benefit of Levetiracetam use during the standard chemoradiation protocol (whole duration, part time, and never subgroups), a Cox proportional hazard model was constructed. We performed a case-matched analysis (1:1) between patients with Levetiracetam use during the whole duration of the standard chemoradiation protocol and patients with Levetiracetam use part time or never according to the following criteria: sex, age, epileptic seizures at diagnosis, RTOG-RPA class, tumor location, preoperative volume, extent of resection, and O6-Methylguanine-DNA methyltransferase promoter methylation status. Patients with unavailable O6-Methylguanine-DNA methyltransferase promoter methylation status (48.5%) were excluded.

RESULTS

460 patients were included. The median overall survival was longer in the 116 patients with Levetiracetam use during the whole duration of the standard chemoradiation protocol (21.0 months; 95%CI, 17.2-24.0) than in the 126 patients with part time Levetiracetam use (16.8 months; 95%CI, 12.4-19.0], and in the 218 patients who never received Levetiracetam (16.0 months; 95%CI, 15.5-19.4; p=0.027). Levetiracetam use during the whole duration of the standard chemoradiation protocol (adjusted Hazard Ratio (aHR) 0.69; 95%CI, 0.52-0.93; p=0.014), O6-Methylguanine-DNA methyltransferase promoter methylation (aHR 0.53; 95%CI, 0.39-0.71; p<0.001), and gross total tumor resection (aHR 0.57; 95%CI, 0.44-0.74; p<0.001) were independent predictors of a longer overall survival. After case matching (n=54 per group), a longer overall survival was found for Levetiracetam use during the whole duration of the standard chemoradiation protocol (HR=0.63; 95%CI, 0.42-0.94, p=0.023).

DISCUSSION

Levetiracetam use during the whole standard chemoradiation protocol possibly improves overall survival of IDH-wildtype glioblastoma patients. It should be considered in the anti-tumor strategy of future multicentric trials.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that in individuals with IDH-wildtype glioblastoma, levetiracetam use throughout the duration of standard chemotherapy is associated with longer median overall survival.

Efficacy of antiepileptic drugs in glioma patients with epilepsy: a systematic review

Background

Comprehensive data on the efficacy and tolerability of antiepileptic drugs (AED) treatment in glioma patients with epilepsy are currently lacking. In this systematic review, we specifically assessed the efficacy of AEDs in patients with a grade II-IV glioma.

Methods

Electronic databases PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane Library were searched up to June 2020. Three different outcomes for both mono- and polytherapy were extracted from all eligible articles: (i) seizure freedom; (ii) ≥50% reduction in seizure frequency; and (iii) treatment failure. Weighted averages (WA) were calculated for outcomes at 6 and 12 months.

Results

A total of 66 studies were included. Regarding the individual outcomes on the efficacy of monotherapy, the highest seizure freedom rate at 6 months was with phenytoin (WA = 72%) while at 12-month pregabalin (WA = 75%) and levetiracetam (WA = 74%) showed highest efficacy. Concerning ≥50% seizure reduction rates, levetiracetam showed highest efficacy at 6 and 12 months (WAs of 82% and 97%, respectively). However, treatment failure rates at 12 months were highest for phenytoin (WA = 34%) and pregabalin (41%). When comparing the described polytherapy combinations with follow-up of ≥6 months, levetiracetam combined with phenytoin was most effective followed by levetiracetam combined with valproic acid.

Conclusion

Given the heterogeneous patient populations and the low scientific quality across the different studies, seizure rates need to be interpreted with caution. Based on the current limited evidence, with the ranking of AEDs being confined to the AEDs studied, levetiracetam, phenytoin, and pregabalin seem to be most effective as AED monotherapy in glioma patients with epilepsy, with levetiracetam showing the lowest treatment failure rate, compared to the other AEDs studied.

Antiseizure medication in patients with Glioblastoma- a collaborative cohort study

PURPOSE

We investigated, whether epileptic seizures (ES) as presenting symptom in adult patients with GBM are associated with better Overall Survival (OS) compared to ES presenting later during the course of GBM, and efficacy and safety of different antiseizure medications (ASMs).

METHODS

Retrospective consecutive cohort study of adults with GBM: 50 from Norway and 50 from Italy. We compared the time to changing ASM treatments. OS was investigated with a Cox regression model adjusted for time dependency.

RESULTS

Median follow-up was 17 months from GBM diagnosis. ES were the presenting symptom in 49 patients. All patients received ASM treatment. LEV was the first ASM in the majority of patients and the most effective at one year from the first prescription, (p = 0.004). Occurrence of adverse events (AEs) was similar between LEV and other ASMs (p = 0.47). Poorer OS correlated with older age at GBM diagnosis, country and ASM therapy. A negative impact of ASMs on OS was observed for LEV in a univariate and multivariate analysis, and for VPA (only in multivariate analysis), even when adjusted for O6-methylguanine-DNA-methyltransferase (MGMT) methylation status. Patients with ES as the onset symptom of GBM and patients who had first ES later had similar OS (p = 0.87).

CONCLUSION

ES as the GBM debut symptom did not lead to a longer OS. LEV was a more effective ASM compared to other treatments with no differences regarding AEs between LEV and other ASMs. Surprisingly, in our patients LEV and VPA were associated with worse OS than other ASMs. This result should be interpreted with caution due to the retrospective nature of this study along with the many variables which may affect the outcome in this population.

Preoperative and early postoperative seizures in patients with glioblastoma-two sides of the same coin?

Background

Symptomatic epilepsy is a common symptom of glioblastoma, which may occur in different stages of disease. There are discrepant reports on association between early seizures and glioblastoma survival, even less is known about the background of these seizures. We aimed at analyzing the risk factors and clinical impact of perioperative seizures in glioblastoma.

Methods

All consecutive cases with de-novo glioblastoma treated at our institution between 01/2006 and 12/2018 were eligible for this study. Perioperative seizures were stratified into seizures at onset (SAO) and early postoperative seizures (EPS, ≤21days after surgery). Associations between patients characteristics and overall survival (OS) with SAO and EPS were addressed.

Results

In the final cohort (n = 867), SAO and EPS occurred in 236 (27.2%) and 67 (7.7%) patients, respectively. SAO were independently predicted by younger age (P = .009), higher KPS score (P = .002), tumor location (parietal lobe, P = .001), GFAP expression (≥35%, P = .045), and serum chloride at admission (>102 mmol/L, P = .004). In turn, EPS were independently associated with tumor location (frontal or temporal lobe, P = .013) and pathologic laboratory values at admission (hemoglobin < 12 g/dL, [P = .044], CRP > 1.0 mg/dL [P = 0.036], and GGT > 55 U/L [P = 0.025]). Finally, SAO were associated with gross-total resection (P = .006) and longer OS (P = .030), whereas EPS were related to incomplete resection (P = .005) and poorer OS (P = .009).

Conclusions

In glioblastoma patients, SAO and EPS seem to have quite different triggers and contrary impact on treatment success and OS. The clinical characteristics of SAO and EPS patients might contribute to the observed survival differences.

Epilepsy in brain metastasis: an emerging entity

PURPOSE OF REVIEW

The purpose of this review is to highlight advances in the management of seizures in brain metastases from solid tumors.

RECENT FINDINGS

The highest risk for seizures is in patients with melanoma and lung cancer. There is lack of data on the efficacy of antiepileptic drugs (AEDs), but interactions between enzyme-inducing AEDs and anticancer agents must be avoided. Levetiracetam and valproic acid are the most appropriate drugs. Prophylaxis with AEDs for patients with brain metastases without a history of seizures is not recommended. Total resection of a brain metastasis allows complete seizure control. Seizures may represent an adverse effect of stereotactic radiosurgery or of high-dose chemotherapy. New preclinical and clinical studies should define the risk of brain metastasis in light of the new treatment options in the different tumor types. New clinical trials should be designed in patients with brain metastases in terms of treatment or prophylaxis of seizures.

Management of epilepsy in brain tumors

Epilepsy in brain tumors (BTE) may require medical attention for a variety of unique concerns: epileptic seizures, possible serious adverse effects of antineoplastic and antiepileptic drugs (AEDs), physical disability, and/or neurocognitive disturbances correlated to tumor site. Guidelines for the management of tumor-related epilepsies are lacking. Treatment is not standardized, and overall management might differ according to different specialists. The aim of this document was to provide directives on the procedures to be adopted for a correct diagnostic-therapeutic path of the patient with BTE, evaluating indications, risks, and benefits. A board comprising neurologists, epileptologists, neurophysiologists, neuroradiologists, neurosurgeons, neuro-oncologists, neuropsychologists, and patients' representatives was formed. The board converted diagnostic and therapeutic problems into seventeen questions. A literature search was performed in September-October 2017, and a total of 7827 unique records were retrieved, of which 148 constituted the core literature. There is no evidence that histological type or localization of the brain tumor affects the response to an AED. The board recommended to avoid enzyme-inducing antiepileptic drugs because of their interference with antitumoral drugs and consider as first-choice newer generation drugs (among them, levetiracetam, lamotrigine, and topiramate). Valproic acid should also be considered. Both short-term and long-term prophylaxes are not recommended in primary and metastatic brain tumors. Management of seizures in patients with BTE should be multidisciplinary. The panel evidenced conflicting or lacking data regarding the role of EEG, the choice of therapeutic strategy, and timing to withdraw AEDs and recommended high-quality long-term studies to standardize BTE care.

An overview of anti-epileptic therapy management of patients with malignant tumors of the brain undergoing radiation therapy

As our surgical, radiation, chemotherapeutic and supportive therapies for brain malignancies improve, and overall survival is prolonged, appropriate symptom management in this patient population becomes increasingly important. This review summarizes the published literature and current practice patterns regarding prophylactic and perioperative anti-epileptic drug use. As a wide range of anti-epileptic drugs is now available to providers, evidence guiding appropriate anticonvulsant choice is reviewed. A particular focus of this article is radiation therapy for brain malignancies. Toxicities and seizure risk associated with cranial irradiation will be discussed. Epilepsy management in patients undergoing radiation for gliomas, glioblastoma multiforme, and brain metastases will be addressed. An emerging but inconsistent body of evidence, reviewed here, indicates that anti-epileptic medications may increase radiosensitivity, and therefore improve clinical outcomes, specifically in glioblastoma multiforme patients.

Choice of antiepileptic drugs affects the outcome in cancer patients with seizures

BACKGROUND

Seizures in cancer patients may occur as a result of CNS primary or metastatic tumor, brain surgery, vascular disease, pharmacologic treatment (including chemotherapy), radiation therapy, or metabolic disorders. The aims of the study were to a) determine whether seizures in cancer patients have prognostic implications and b) study patient outcome based on the antiepileptic drug used.

METHOD

This is a prospective comparative study that included adult cancer patients with and without seizures from May 2010 to November 2016 seen by the neuro-oncology unit at a cancer referral center. Variables included age, gender, oncologic characteristics, seizure features, treatment, and outcome. Parametric and non-parametric tests were used to compare groups, and Kaplan-Meier curves with the log-rank test were used to analyze survival. Cox multivariate regression tests were used to describe survival and compare groups.

RESULTS

A total of 823 patients were included; 419 (51%) patients had at least one seizure and were compared with 404 (49%) who did not experience seizures. Of the seizure group, 53% had brain metastases, 36% did not have a brain tumor, and 11% had a primary brain tumor. No survival differences were noted among patients with brain metastases or primary tumor with or without seizures. In the seizure group, 249 (59%) required only one antiepileptic drug, whereas 134 (32%) required 2 or more. A better overall survival was identified for patients prescribed carbamazepine (p = 0.02), lamotrigine (p = 0.015), levetiracetam (p = 0.03), and valproic acid (p = 0.009).

CONCLUSIONS

Patients with primary or metastatic brain tumors have the same overall survival with or without seizures. However, patients with seizures not treated with antiepileptics exhibit worse overall survival.

Antiepileptic treatment and survival in newly diagnosed glioblastoma patients: Retrospective multicentre study in 285 Italian patients

Glioblastoma multiforme (GBM) has a dismal prognosis even with the best available treatment. Different studies have suggested a possible impact of antiepileptic drugs (AED) on survival in patients with GBM. A recent pooled analysis of prospective clinical trials in newly diagnosed GBM found no significant survival benefit in GBM patients treated with AED. We performed a retrospective study on adult patients with GBM in order to evaluate the impact of AED therapy on overall survival (OS), after adjusting for known prognostic factor (age, extent of surgery, Karnofsky performance status, radiochemotherapy). A total of 285 patients were analyzed. Of them 144 received a non-enzyme-inducing (NEIAED) and 95 an enzyme-inducing AED (EIAED). At univariate analysis the OS of patients receiving AED was not significantly different from that of patients not receiving an AED (HR 0.98, 95%CI 0.69-1.4, p = 0.925), moreover OS was not significantly different between patients receiving EIAED or NEIAED. At multivariate analysis a trend to more prolonged survival (HR 0.8, 95% CI 0.59-1.08, p = 0.15) was detected in patients treated with NEIAED. The question whether treatment with AED may increase OS in GBM patients remains unanswered and randomized extremely large controlled clinical trial would be necessary to elucidate the possible impact of AED on prognosis. In the meantime the use of AED in GBM patients, based on the presumed potential antitumour activity, is not recommended.

Efficacy and safety of Levetiracetam vs. other antiepileptic drugs in Hispanic patients with glioblastoma

Epilepsy is a common symptom in patients with glioblastoma (GB). 213 patients with GB from RedLANO follow-up registry were included. All patients underwent surgery, if feasible, followed by chemoradiation based on temozolomide (Stupp platform). Information was recorded regarding demographics, seizure timing, anti-epileptic drugs (AEDs), dosage, time to next seizure, total seizures in 6 months, and main side effects of AEDs. The relationship between epilepsy treatment and overall survival (OS) was evaluated. Mean age was 53 years old and 56.8% were male. Seventy-eight patients (37%) were treated with levetiracetam (LEV), 27% were given another AED and 36% did not require any AED. Choice of AED was not associated with age (p = 0.67), performance status (p = 0.24) or anatomic tumor site (p = 0.34). Seizures and AED requirement were greater in those having primary GB (p = 0.04). After starting an AED, the mean time until next crisis was 9.9 days (SD ± 6.3), which was shorter in those receiving LEV (p = 0.03); mean number of seizures during the first 3 and 6 months were 2.9 and 4, respectively. Most patients treated with LEV (n = 46) required less than two medication adjustments compared to those treated with other AEDs (p = 0.02). Likewise, less patients exposed to LEV required a coadjuvant drug (p = 0.04). Additionally, patients receiving LEV had significantly less adverse effects compared to patients treated with another AED. OS was significantly higher in the group treated with LEV compared to other AEDs (25.5 vs. 17.9 months; p = 0.047). Patients treated with LEV had better seizure control and longer OS compared to other AEDs.

In vitro antineoplastic effects of brivaracetam and lacosamide on human glioma cells

Background

Epilepsy is a frequent symptom in patients with glioma. Although treatment with antiepileptic drugs is generally effective in controlling seizures, drug-resistant patients are not uncommon. Multidrug resistance proteins (MRPs) and P-gp are over-represented in brain tissue of patients with drug-resistant epilepsy, suggesting their involvement in the clearance of antiepileptic medications. In addition to their anticonvulsant action, some drugs have been documented for cytotoxic effects. Aim of this study was to evaluate possible in vitro cytotoxic effects of two new-generation antiepileptic drugs on a human glioma cell line U87MG.

Methods

Cytotoxicity of brivaracetam and lacosamide was tested on U87MG, SW1783 and T98G by MTS assay. Expression of chemoresistance molecules was evaluated using flow cytometry in U87MG and human umbilical vein endothelial cells (HUVECs). To investigate the putative anti-proliferative effect, apoptosis assay, microRNA expression profile and study of cell cycle were performed.

Results

Brivaracetam and lacosamide showed a dose-dependent cytotoxic and anti-migratory effects. Cytotoxicity was not related to apoptosis. The exposure of glioma cells to brivaracetam and lacosamide resulted in the modulation of several microRNAs; particularly, the effect of miR-195-5p modulation seemed to affect cell cycle, while miR-107 seemed to be implicated in the inhibition of cells migration. Moreover, brivaracetam and lacosamide treatment did not modulate the expression of chemoresistance-related molecules MRPs1-3-5, GSTπ, P-gp on U87MG and HUVECs.

Conclusion

Based on antineoplastic effect of brivaracetam and lacosamide on glioma cells, we assume that patients with glioma could benefit by the treatment with these two molecules, in addition to standard therapeutic options.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0546-9) contains supplementary material, which is available to authorized users.

Pattern of care and outcome in elderly patients with glioblastoma: Data in 151 patients from 3 Lombardia Hospitals

The appropriate treatment approach for elderly patients with glioblastoma multiforme (GBM) is unclear, although different studies suggest survival benefit in fit patients treated with radiotherapy and chemiotherapy after surgery. We performed a retrospective analysis of 151 patients older than 65years with GBM treated in 3 Lombardia Hospitals. In univariate regression analysis higher KPS (p=0.02), macroscopical total resection (p<0.003), radiotherapy (p<0.0001), chemotherapy (p<0.0001) and second line chemotheraphy (p=0.02) were of positive prognostic value. On the contrary older age (>70years), presence of seizure at onset and additional resection after tumor recurrence did not influence OS. Multivariate analysis revealed radiotherapy (HR 0.2 p<0.0001) and extent of surgery (HR 0.3, p=0,0063) as positive independent prognostic factors. Patients receiving radio-chemiotherapy displayed more treatment-related toxicities with a slightly prolonged OS versus those receiving hypofractionated radiotherapy. With the limits of a retrospective study, our data suggest that in elderly fit patients extensive surgery should be considered, moreover adjuvant treatments led to an increase in OS. Randomized controlled study are needed to develop treatment guidelines for elderly GBM patients and to assess whether the combination of post-surgical radio and chemiotherapy may be superior to hypofractionated radiotherapy and chemiotherapy in fit patients.

Anticonvulsant therapy in brain-tumor related epilepsy

Background. The lifetime risk of patients with brain tumors to have focal epileptic seizures is 10-100%; the risk depends on different histology. Specific guidelines for drug treatment of brain tumor-related seizures have not yet been established.

Aim. This review addresses the special aspects of antiepileptic drug (AED) therapy in brain tumor-related epilepsy.

Methods. We analyzed the literature up to December 2015.

Results. Based on current evidence the management of tumor-related seizures does not differ substantially from that applied to epilepsies from other etiologies. Therefore, the choice of an AED is based, above all, on tolerability and pharmacokinetic interactions with chemotherapeutic drugs. Levetiracetam is recommended by many authors as first-line therapy in brain tumor-related epilepsy. Due to the possibility of interactions, the combination of enzyme-inducing AEDs and chemotherapeutic drugs, is usually not recommended as a first choice. Currently there is no evidence that prophylactic prescription of long-term AEDs in brain tumor-patients who did not present with seizures is justified. Because of the high risk of recurrence, however, AED treatment should be strongly considered after a single brain tumor-related seizure. The decision to withdraw AEDs must carefully consider the risk of seizure recurrence.

Conclusion. At present levetiracetam is the preferred drug in brain tumor-related epilepsy, especially when drug interactions need to be avoided. In the future we hope to acquire more targeted drugs against this disorder by uncovering its pathogenesis.

Incidence, Characteristics, and Implications of Seizures in Patients With Glioblastoma

BACKGROUND

Seizures in patients with glioblastoma are associated with worse quality of life. However, their incidence, clinical characteristics, and prognostic implications are less well characterized.

OBJECTIVE

This study was undertaken to provide a contemporary experience along with benchmark data relevant to the above in patients with glioblastoma. It also sought to reexplore improved survival with seizures, as observed by others.

METHODS

In this single-institution study, patients with glioblastoma from 2010 through 2014 had their medical records reviewed in detail.

RESULTS

Among 122 patients, 58 (48%) had a seizure history. Of these, 67% had more than 1, 41% had generalized seizures, and most received antiseizure medication (most commonly levetiracetam). The median survival for patients with seizures was 1.66 years and 0.87 years for those without (hazard ratio for risk of death with seizures: 0.72; 95% confidence interval: 0.43, 1.21; P = .22 by the log-rank test).

CONCLUSION

Seizures are common in patients with glioblastoma and, in contrast to earlier reports, are not associated with a statistically significant improvement in survival.

Does Valproic Acid or Levetiracetam Improve Survival in Glioblastoma? A Pooled Analysis of Prospective Clinical Trials in Newly Diagnosed Glioblastoma

PURPOSE

Symptomatic epilepsy is a common complication of glioblastoma and requires pharmacotherapy. Several uncontrolled retrospective case series and a post hoc analysis of the registration trial for temozolomide indicated an association between valproic acid (VPA) use and improved survival outcomes in patients with newly diagnosed glioblastoma.

PATIENTS AND METHODS

To confirm the hypothesis suggested above, a combined analysis of survival association of antiepileptic drug use at the start of chemoradiotherapy with temozolomide was performed in the pooled patient cohort (n = 1,869) of four contemporary randomized clinical trials in newly diagnosed glioblastoma: AVAGlio (Avastin in Glioblastoma; NCT00943826), CENTRIC (Cilengitide, Temozolomide, and Radiation Therapy in Treating Patients With Newly Diagnosed Glioblastoma and Methylated Gene Promoter Status; NCT00689221), CORE (Cilengitide, Temozolomide, and Radiation Therapy in Treating Patients With Newly Diagnosed Glioblastoma and Unmethylated Gene Promoter Status; NCT00813943), and Radiation Therapy Oncology Group 0825 (NCT00884741). Progression-free survival (PFS) and overall survival (OS) were compared between: (1) any VPA use and no VPA use at baseline or (2) VPA use both at start of and still after chemoradiotherapy. Results of Cox regression models stratified by trial and adjusted for baseline prognostic factors were analyzed. The same analyses were performed with levetiracetam (LEV).

RESULTS

VPA use at start of chemoradiotherapy was not associated with improved PFS or OS compared with all other patients pooled (PFS: hazard ratio [HR], 0.91; 95% CI, 0.77 to 1.07; P = .241; OS: HR, 0.96; 95% CI, 0.80 to 1.15; P = .633). Furthermore, PFS and OS of patients taking VPA both at start of and still after chemoradiotherapy were not different from those without antiepileptic drug use at both time points (PFS: HR, 0.92; 95% CI, 0.74 to 1.15; P = .467; OS: HR, 1.10; 95% CI, 0.86 to 1.40; P = .440). Similarly, no association with improved outcomes was observed for LEV use.

CONCLUSION

The results of this analysis do not justify the use of VPA or LEV for reasons other than seizure control in patients with newly diagnosed glioblastoma outside clinical trials.

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.

Antiepileptic drugs in patients with malignant brain tumor: beyond seizures and pharmacokinetics

In neurological malignancies, antiepileptic drugs (AEDs) are frequently used to control the seizure activity that accompanies the disorder. There is a growing body of evidence on the importance of AED selection for reasons other than pharmacokinetics (PK) properties. Epigenetic modifications may occur in glioblastomas, such as changes in gene methylation and histone acetylation states. Secondary mechanisms of AED drug action which impact these epigenetic modifications could play a significant role in patient survival outcomes. Both valproic acid (VPA) and carbamazepine have histone deacetylase (HDAC) inhibitory activities, and levetiracetam and VPA reduce the activity of O6-methylguanine-DNA methyltransferase (MGMT), a DNA-repair molecule implicated in resistance to alkylating agents used for chemotherapy. The use of AEDs for purposes other than seizure prophylaxis and their selection based on non-PK properties present a potential paradigm shift in the field of neuro-oncology.

Repurposing some older drugs that cross the blood-brain barrier and have potential anticancer activity to provide new treatment options for glioblastoma

Glioblastoma is a brain neoplasm with limited 5-year survival rates. Developments of new treatment regimens that improve patient survival in patients with glioblastoma are needed. It is likely that a number of existing drugs used in other conditions have potential anticancer effects that offer significant survival benefit to glioblastoma patients. Identification of such drugs could provide a novel treatment paradigm.

Antiepileptic drug use improves overall survival in breast cancer patients with brain metastases in the setting of whole brain radiotherapy

BACKGROUND AND PURPOSE

There is mounting evidence that histone deacetylase (HDAC) inhibitors, e.g. valproic acid (VPA), synergize with radiation to improve outcomes in several cancers. This study was conducted to ascertain whether VPA affected outcomes in breast cancer patients with brain metastases treated with whole brain radiotherapy (WBRT).

MATERIALS AND METHODS

Records from 253 breast cancer patients with brain metastases treated with WBRT were reviewed. Data regarding use of all antiepileptic drugs (AEDs) were extracted. Kaplan-Meier survival times were calculated using the date of brain involvement as time zero. Cox proportional hazard models were used to determine the association between patient and tumor characteristics and overall survival (OS).

RESULTS

Median OS for the entire patient cohort was 6 months. Patients receiving VPA (n=20) had a median OS of 11 months versus 5 months for those not receiving VPA (p=0.028). Median OS was 9 months for patients taking any AED (n=101) versus 4 months for those not taking AEDs (p=0.0003). On multivariate analysis both VPA and AED use were associated with improved OS (HR 0.61, p=0.0419; HR 0.59, p=0.0002, respectively).

CONCLUSIONS

This study suggests the use of AEDs, including VPA, is associated with improved OS in breast cancer patients with brain metastases following WBRT.

Prognostic relevance of epilepsy at presentation in glioblastoma patients

BACKGROUND

Epileptogenic glioblastomas are thought to convey a favorable prognosis, either due to early diagnosis or potential antitumor effects of antiepileptic drugs. We investigated the relationship between survival and epilepsy at presentation, early diagnosis, and antiepileptic drug therapy in glioblastoma patients.

METHODS

Multivariable Cox regression was applied to survival data of 647 consecutive patients diagnosed with de novo glioblastoma between 2005 and 2013 in order to investigate the association between epilepsy and survival in glioblastoma patients. In addition, we quantified the association between survival and valproic acid (VPA) treatment.

RESULTS

Epilepsy correlated positively with survival (HR: 0.75 (95% CI: 0.61-0.92), P < .01). This effect is independent of age, sex, performance status, type of surgery, adjuvant therapy, tumor location, and tumor volume, suggesting that this positive correlation cannot be attributed solely to early diagnosis. For patients who presented with epilepsy, the use of the antiepileptic drug VPA did not associate with survival when compared with patients who did not receive VPA treatment.

CONCLUSION

Epilepsy is an independent prognostic factor for longer survival in glioblastoma patients. This prognostic effect is not solely explained by early diagnosis, and survival is not associated with VPA treatment.

Quantification of the impact of enzyme-inducing antiepileptic drugs on irinotecan pharmacokinetics and SN-38 exposure

The population pharmacokinetic model reported here was developed using data from 2 phase 2 trials of irinotecan for treatment of malignant glioma to quantify the impact of concomitant therapy with enzyme-inducing antiepileptic drugs (EIAEDs) on irinotecan pharmacokinetics. Patients received weekly irinotecan doses of 100 to 400 mg/m(2) , and plasma samples were collected and analyzed for irinotecan and its APC, SN-38, and SN-38G metabolites. Nonlinear mixed-effects modeling was employed for population pharmacokinetic analysis. Concomitant therapy with phenytoin, phenobarbital, or carbamazepine increased the clearances of irinotecan, SN-38, and SN-38G but not APC. SN-38 clearance was 2-fold higher with concomitant EIAED use, resulting in 40% lower SN-38 exposure. Evaluation of additional covariates revealed no clinically relevant effects of sex or concomitant corticosteroid use. The population pharmacokinetic model suggests that a 1.7-fold increase in irinotecan dose may compensate for decreases in SN-38 exposure in the presence of concomitant EIAEDs. Although slightly more conservative, this dose adjustment is consistent with those recommended based on increases in the maximally tolerated dose for malignant glioma patients receiving EIAEDs and may be an appropriate starting point for further investigation when extrapolating to other cancer types or alternative regimens.

Survival benefit of levetiracetam in patients treated with concomitant chemoradiotherapy and adjuvant chemotherapy with temozolomide for glioblastoma multiforme

BACKGROUND

A chemosensitizing effect of levetiracetam (LEV) has been suggested because LEV inhibits O-6 methylguanine-DNA methyltransferase (MGMT). However, the survival benefit of LEV has not been clinically documented. The objective of this study was to assess the survival benefit of LEV compared with other antiepileptic drugs as a chemosensitizer to temozolomide for patients with glioblastoma.

METHODS

In total, 103 consecutive patients with primary glioblastoma who received concomitant chemoradiotherapy and adjuvant chemotherapy with temozolomide were retrospectively reviewed, and 58 patients (56%) received LEV during temozolomide chemotherapy for at least 3 months. A Cox regression survival analysis was performed to adjust for confounding factors, including age, extent of lesion, Karnofsky performance scale score, extent of removal, and MGMT promoter methylation status.

RESULTS

The median progression-free survival (PFS) and overall survival (OS) for patients who received LEV in combination with temozolomide (PFS: median, 9.4 months; 95% confidence interval [CI], 7.5-11.3 months; OS: median, 25.7 months; 95% CI, 21.7-29.7 months) were significantly longer than those for patients who did not receive LEV (PFS: median, 6.7 months; 95% CI, 5.8-7.6 months; OS: median, 16.7 months; 95% CI, 12.1-21.3 months; P = .010 and P = .027, respectively). In multivariate analysis, the variables that were identified as significant prognostic factors for OS were preoperative Karnofsky performance scale score (hazard ratio [HR], 0.37; P = .016), MGMT promoter methylation (HR, 0.30; P = .002), and receipt of LEV (HR, 0.31; P < .001.

CONCLUSIONS

LEV may provide a survival benefit in patients with glioblastoma who receive temozolomide-based chemotherapy. A prospective randomized study may be indicated.

Risk factors for seizures and antiepileptic drug-associated adverse effects in high-grade glioma patients: A multicentre, retrospective study in Hong Kong

Aim

The aim of this present study was to determine the frequency, as well as risk factors, for seizures and antiepileptic drug (AED)-associated adverse effects among high-grade glioma (HGG) patients.

Patients and Methods

A multicentre, retrospective study of adult Chinese Hong Kong patients from three neurosurgical centres diagnosed with supratentorial HGG between 1 January 2001 and 31 December 2010 was performed.

Results

A total of 198 patients, with a mean age of 55 years (range: 18–88) and a mean follow up of 15 months, was recruited. Most suffered from glioblastoma multiforme (GBM) (63 per cent) followed by anaplastic astrocytoma (25 per cent). Median overall survival for patients with GBM was 8 months, and 11 months for those with grade III gliomas. Prophylactic AED was prescribed in 165 patients (83 per cent), and 64 per cent of patients were continued until end of life or last follow up. A total of 112 patients (57 per cent) experienced seizures at a mean duration of 8 months postoperatively (range: 1 day–75 months). Independent predictors for seizures were a diagnosis of GBM [adjusted odds ratio (OR): 2.33, 95 per cent confidence interval (CI): 1.21–4.52] and adjuvant radiotherapy (adjusted OR: 2.97, 95 per cent CI: 1.49–6.62). One-fifth of patients (21 per cent) experienced AED adverse effects, with idiosyncratic cutaneous reactions and hepatotoxicity most frequently observed. An independent predictor for adverse effects was exposure to aromatic AED, such as phenytoin, carbamazepine and phenobarbital (adjusted OR: 3.32, 95 per cent CI: 1.32–8.40).

Conclusions

Antiepileptic drug prescription for primary seizure prophylaxis is both pervasive and prolonged for HGG patients. Seizures occur frequently, but most were delayed and none were life threatening. Judicious prescription of AED is required, especially when a significant proportion of patients experience adverse effects. Patients with a diagnosis of GBM and exposure to radiotherapy are at risk. We suggest, contrary to present practice, that primary seizure prophylaxis be given only during the perioperative period and resumed when they occur. We also recommend avoidance of aromatic AED due to their association with idiosyncratic adverse effects.

Palliative and supportive care for glioma patients

The diagnosis of a brain tumor is a life-changing event for patients and families. High-grade gliomas are incurable and long-term survival remains limited. While low-grade glioma patients have better outcomes, their quality of life is often affected by a variety of symptoms as well. Helping glioma patients improve quality of life at all stages of illness is an important goal for the interdisciplinary care team. There is evidence from advanced lung cancer patients that early involvement of a palliative care team can improve patient's quality of life, symptom burden, and even survival and a similar approach benefits glioma patients as well. Patients with high-grade and low-grade glioma often suffer from significant symptom burden. We discuss how validated global symptom assessments and symptom-specific screening tools are useful to identify distressing symptoms. Seizures, fatigue, depression, and anxiety are some of the more common symptoms throughout the disease course and should be managed actively. Patients with glioma also have high symptom burden at the end of life and the majority lose decision-making capacity. Advance care planning conversations early in the disease course are essential to elicit the patient's wishes for end of life care and effective communication with surrogate decision makers during all stages of the disease helps ensure that those wishes are respected.

Seizure prognosis in brain tumors: new insights and evidence-based management

Brain tumor-related epilepsy (BTE) is common in low- and high-grade gliomas. The risk of seizures varies between 60% and 100% among low-grade gliomas and between 40% and 60% in glioblastomas. The presence of seizures in patients with brain tumors implies favorable and unfavorable factors. New-onset seizures represent an early warning sign for the presence of a brain tumor and count as a good prognostic factor for survival. Recurrence or worsening of seizures during the course of disease may signal tumor progression. Each of the modalities for tumor control (i.e., surgery, radiotherapy, chemotherapy) contributes to seizure control. Nevertheless, one third of BTE shows pharmacoresistance to antiepileptic drugs (AEDs) and may severely impair the burden of living with a brain tumor. For symptomatic therapy of BTE, seizure type and individual patient factors determine the appropriate AED. Randomized controlled trials in partial epilepsy in adults to which type BTE belongs and additional studies in gliomas indicate that levetiracetam is the agent of choice, followed by valproic acid (VPA). In the case of recurring seizures, combining these two drugs (polytherapy) seems effective and possibly synergistic. If either one is not effective or not well tolerated, lacosamide, lamotrigine, or zonisamide are additional options. A new and exciting insight is the potential contribution of VPA to prolonged survival, particularly in glioblastomas. A practice guideline on symptomatic medical management including dose schedules of AEDs is supplied.

Erlotinib: early clinical development in brain cancer

INTRODUCTION

Glioblastoma (GBM) is the most common brain cancer in adults. It is also, unfortunately, the most aggressive type and the least responsive to therapy. Overexpression of EGFR and/or EGFRvIII is frequently found in GBM and is frequently associated with the more malignant phenotype of the disease and a poor clinical outcome. EGFR-targeted therapy represents a promising anti-GBM therapy. Two EGFR kinase inhibitors, gefitinib and erlotinib have been tested in clinical trials for malignant gliomas. However, the clinical efficacy of EGFR-targeted therapy has been only modest in GBM patients.

AREAS COVERED

The authors provide an evaluation of erlotinib as a potential therapy for GBM. The authors highlight experiences drawn from clinical trials and discuss the challenges, which include the insufficient penetration through the blood-brain barrier (BBB) and chemoresistance.

EXPERT OPINION

Malignant brain tumours have a very complex signalling network that is not only driven by EGFR. This complexity dictates tumour sensitivity to EGFR-targeted therapies. Alternative kinase signalling pathways may be involved in parallel with the inhibited target, so that a single target's inactivation is not sufficient to block downstream oncogenic signalling. The use of nanocarriers offers many opportunities, such as the release of the drug to specific cells or tissues, together with the ability to overcome different biological barriers, like the BBB.

Treatment of epileptic seizures in brain tumors: a critical review

Epileptic seizures represent a common signal of intracranial tumors, frequently the presenting symptom and the main factor influencing quality of life. Treatment of tumors concentrates on survival; antiepileptic drug (AED) treatment frequently is prescribed in a stereotyped way. A differentiated approach according to epileptic syndromes can improve seizure control and minimize unwarranted AED effects. Prophylactic use of AEDs is to be discouraged in patients without seizures. Acutely provoked seizures do not need long-term medication except for patients with high recurrence risk indicated by distinct EEG patterns, auras, and several other parameters. With chronically repeated seizures (epilepsies), long-term AED treatment is indicated. Non-enzyme-inducing AEDs might be preferred. Valproic acid exerts effects against progression of gliomatous tumors. In low-grade astrocytomas with epilepsy, a comprehensive presurgical epilepsy work-up including EEG-video monitoring is advisable; in static non-progressive tumors, it is mandatory. In these cases, the neurosurgical approach has to include the removal of the seizure-onset zone frequently located outside the lesion.

Tumour associated epilepsy and glutamate excitotoxicity in patients with gliomas

Tumour associated epilepsy (TAE) is common, debilitating and often not successfully controlled by surgical resection of the tumour and administration of multiple anti-epileptic drugs. It represents a cause of significant lost quality of life in an incurable disease and is therefore an important subject for ongoing research. The pathogenesis of TAE is likely to be multifactorial and involve, on the microscopic level, the interaction of genetic factors, changes in the peritumoural microenvironment, alterations in synaptic neurotransmitter release and re-uptake, and the excitotoxic effects of glutamate. On a macroscopic level, the occurrence of TAE is likely to be influenced by tumour size, location and interaction with environmental factors. The optimal treatment of TAE requires a multi-disciplinary approach with input from neurosurgeons, neurologists, radiologists, pathologists and basic scientists. This article reviews the current literature regarding the incidence, treatment, and aetiology of TAE.

Tumor associated seizures in glioblastomas are influenced by survival gene expression in a region-specific manner: a gene expression imaging study

Tumor associated seizures (TAS) are common and cause significant morbidity. Both imaging and gene expression features play significant roles in determining TAS, with strong interactions between them. We describe gene expression imaging tools which allow mapping of brain regions where gene expression has significant influence on TAS, and apply these methods to study 77 patients who underwent surgical evaluation for supratentorial glioblastomas. Tumor size and location were measured from MRI scans. A 9-set gene expression profile predicting long-term survivors was obtained from RNA derived from formalin-fixed paraffin embedded tissue. A total of 32 patients (42%) experienced preoperative TAS. Tumor volume was smaller (31.1 vs. 58.8 cubic cm, p<0.001) and there was a trend toward median survival being higher (48.4 vs. 32.7 months, p=0.055) in patients with TAS. Although the expression of only OLIG2 was significantly lower in patients with TAS in a groupwise analysis, gene expression imaging analysis revealed regions with significantly lower expression of OLIG2 and RTN1 in patients with TAS. Gene expression imaging is a powerful technique that demonstrates that the influence of gene expression on TAS is highly region specific. Regional variability should be evaluated with any genomic or molecular markers of solid brain lesions.

Optimizing antiepileptic drug treatment in tumoral epilepsy

Between 30% and 50% of patients with brain tumors first present with a seizure, and up to 30% more will develop seizures later. Therefore, optimal management of these patients requires a rational approach to the use of antiseizure medications. Based on current evidence, prophylactic prescription of long-term antiepileptic drugs (AEDs) in patients with brain tumors in patients who did not present with seizures is not justified. Because of the high risk of recurrence, however, AED treatment should be strongly considered after a single seizure considered to be due to a tumor. Because of the lack of well-controlled randomized trials, the decision on which AED provides the best risk-benefit ratio in the individual patient is based mostly on physician's judgment rather than sound scientific evidence. In patients who may require chemotherapy, a non-enzyme-inducing AED is preferred for initial treatment to minimize the risk of drug interactions that impact adversely on the outcome of anticancer chemotherapy. Several retrospective studies in seizure patients with glioblastoma treated with chemotherapy have provided evidence for a moderately improved survival with the use of valproic acid, possibly due to inhibition of histone deacetylase. However, valproic acid may also increase the hematologic toxicity of antineoplastic drugs, presumably by inhibiting their metabolism, and may independently impair hemostasis, which is of some concern for patients who require surgical intervention. Among newer generation AEDs, levetiracetam has a number of advantageous features, including availability of a parenteral formulation, but other agents such as gabapentin, lamotrigine, oxcarbazepine, topiramate, and zonisamide may also be considered. Potentially more effective treatments targeting specific mechanisms of epileptogenesis and ictogenesis are being investigated. Resection of the tumor, radiation therapy, or chemotherapy can bring refractory seizures under control or prolong the duration of seizure freedom, an effect that does not appear to be necessarily related to removal or shrinkage of the tumor mass. In patients with a successfully treated tumor and an overall good prognosis for long-term survival, gradual discontinuation of AEDs may be considered.

Epilepsy in glioblastoma patients: basic mechanisms and current problems in treatment

Glioblastoma-related epilepsy requires paying careful attention to a combination of factors with an integrated approach. Major interrelated issues must be considered in the seizure care of glioblastoma patients. Seizure control frequently requires the administration of antiepileptic drugs simultaneously with other treatments, including surgery, radiotherapy and chemotherapy, with complete seizure relief often being difficult to achieve. The pharmacological interactions between antiepileptic drugs and antineoplastic agents can modify the activity of both treatments, compromising their efficacy and increasing the probability of developing adverse events related to both therapies. This review summarizes the new pathophysiological pathways involved in the epileptogenesis of glioblastoma-related seizures and the interactions between antiepileptic drugs and oncological treatment, paying special attention to its impact on survival and the current evidence of the antiepileptic treatment efficacy, including the potential usefulness of new third-generation compounds.

Impact of particular antiepileptic drugs on the survival of patients with glioblastoma multiforme

OBJECT

Glioblastoma multiforme (GBM) is the most common astrocytic brain tumor and carries a dire prognosis. Despite current therapeutic options--surgery, radiotherapy, and chemotherapy--survival varies from 11.3 to 14.6 months. A group of drugs known as histone deacetylase inhibitors (HDIs) has demonstrated a potentially beneficial role in cancer treatment, particularly in combination with other therapies. A drug that exhibits potential as an HDI is sodium valproate (VPA), which is frequently used to treat seizures in patients with cerebral neoplasms. The present study was undertaken to investigate the role of VPA as an antitumor agent in the management of patients with GBM.

METHODS

A review was conducted in terms of how HDIs work, the use of antiepileptic drugs (AEDs), and the effects of AEDs on survival in a local cohort of patients diagnosed with GBM. The local cohort of patients was determined by reviewing the electronic histopathology and AED informatics systems. A meta-analysis of papers on the use of AEDs in GBM was also performed.

RESULTS

The local cohort consisted of 236 patients with GBM, 210 of whom had complete data available for analysis, a median age of 62 years, and 1-year survival of 26%. Patients treated with AEDs had a significantly longer survival than those who were not (Mantel-Cox log-rank test 19.617, p < 0.001). Those treated with VPA had significantly longer survival than those who did not receive an AED (Mantel-Cox log-rank test 17.506, p < 0.001), and patients treated with VPA had a significantly longer survival than those who had received other AEDs (Mantel-Cox log-rank test 5.303, p < 0.02).

CONCLUSIONS

Authors of this study demonstrated evidence supporting the theory that VPA may benefit patients with GBM in terms of survival.

Epilepsy meets cancer: when, why, and what to do about it?

The lifetime risk of having epileptic seizures is profoundly increased in patients with cancer: about 20% of all patients with systemic cancer may develop brain metastases. These patients and those with primary brain tumours have a lifetime risk of epilepsy of 20-80%. Moreover, exposure to chemotherapy or radiotherapy to the brain, cancer-related metabolic disturbances, stroke, and infection can provoke seizures. The management of epilepsy in patients with cancer includes diagnosis and treatment of the underlying cerebral pathological changes, secondary prophylaxis with antiepileptic drugs, and limiting of the effect of epilepsy and its treatment on the efficacy and tolerability of anticancer treatments, cognitive function, and quality of life. Because of the concern of drug-drug interactions, the pharmacological approach to epilepsy requires a multidisciplinary approach, specifically in a setting of rapidly increasing choices of agents both to treat cancer and cancer-associated epilepsy.

[Glioma-associated epilepsy]

BACKGROUND

Epileptic seizures are a common symptom in patients with primary brain tumours of the glioma type. The paper presents a discussion of epileptogenesis, choice of medication and follow-up of these patients.

METHOD

The article is based on a search in PubMed and selection of articles based on the authors' discretionary judgement and clinical experience with this patient group.

RESULTS

Epileptic seizures are a common symptom of glioma, particularly the low-grade types. The background to glioma-associated epilepsy is multifactorial, and the molecular biological characteristics of the tumour probably play a central part in the epileptogenesis. Effective treatment of epileptic seizures is of great importance to the quality of life of the glioma patient. Seizure frequency and the effectiveness of anti-epileptic treatment vary, and some patients require treatment with several anti-epileptic drugs. Surgical and oncological treatment of the tumour will also often reduce the frequency of seizures.

CONCLUSION

As a general rule, antiepileptics without enzyme-inducing properties and with low protein-binding should be preferred for glioma patients. This will reduce the risk of interactions with chemotherapy or steroid therapy. Patients with brain tumours are particularly vulnerable to the effects on wakefulness, moods and cognition, and this should be borne in mind in the choice of medication and in follow-up. Haematological status should be monitored particularly closely when there is concomitant use of chemotherapy and antiepileptic drugs that may affect the bone marrow function.

Characteristics and treatment of seizures in patients with high-grade glioma: a review

High-grade gliomas (HGGs), including anaplastic astrocytoma and glioblastoma multiforme, are the most common primary brain tumors, and are often associated with seizures. Seizure control is a critical but often underappreciated goal in the treatment of patients harboring these malignant lesions. Patients with HGG who also have medically intractable seizures should be considered for a palliative resection guided by electrocorticography and functional mapping. Antiepileptic drugs remain the mainstay of seizure treatment in HGG, and antiepileptic medication should be started after a tumor-related seizure, but should not be used prophylactically in the absence of seizure activity.

Brain tumor-related epilepsy

In patients with brain tumor (BT), seizures are the onset symptom in 20-40% of patients, while a further 20-45% of patients will present them during the course of the disease. These patients present a complex therapeutic profile and require a unique and multidisciplinary approach. The choice of antiepileptic drugs is challenging for this particular patient population because brain tumor-related epilepsy (BTRE) is often drug-resistant, has a strong impact on the quality of life and weighs heavily on public health expenditures.In BT patients, the presence of epilepsy is considered the most important risk factor for long-term disability. For this reason, the problem of the proper administration of medications and their potential side effects is of great importance, because good seizure control can significantly improve the patient's psychological and relational sphere. In these patients, new generation drugs such as gabapentin, lacosamide, levetiracetam, oxcarbazepine, pregabalin, topiramate, zonisamide are preferred because they have fewer drug interactions and cause fewer side effects. Among the recently marketed drugs, lacosamide has demonstrated promising results and should be considered a possible treatment option. Therefore, it is necessary to develop a customized treatment plan for each individual patient with BTRE. This requires a vision of patient management concerned not only with medical therapies (pharmacological, surgical, radiological, etc.) but also with emotional and psychological support for the individual as well as his or her family throughout all stages of the illness.

Why dapsone stops seizures and may stop neutrophils' delivery of VEGF to glioblastoma

Lopez-Gomez et al. recently published remarkable but mechanistically unexplained empirical evidence that the old antibiotic dapsone has antiepileptic activity. We addressed the question "Why should a sulfone antibiotic reduce seizures?". We report here our conclusions based on data from past studies that seizures are associated with elevated interleukin-8 (IL-8) and that dapsone inhibits IL-8 release and function in several different clinical and experimental contexts. Diverse CNS insults cause an increase in CNS IL-8. Thus, the pro-inflammatory environment generated by increase IL-8 leads to a lower seizure threshold. Together this evidence indicates dapsone exerts anti-seizure activity by diminishing IL-8 signalling. Since IL-8 is clearly upregulated in glioblastoma and contributes to the florid angiogenesis of that disease, and since interference with IL-8 function has been shown to inhibit glioblastoma invasion and growth in several experimental models, and dapsone has been repeatedly been shown to clinically inhibit IL-8 function when used to treat human neutrophilic dermatoses, we believe that dapsone thereby reduces seizures by countering IL-8 function and may similarly retard glioblastoma growth by such anti-IL-8 function.

Valproic acid affected the survival and invasiveness of human glioma cells through diverse mechanisms

The effects of valproic acid (VPA) on the viability, apoptosis, and invasiveness of two glioma cells (A172 and T98G) and the underlying mechanisms were studied. VPA induced cytotoxicity and apoptosis, and suppressed the invasiveness of both cells. VPA increased the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9 in A172 cells, but decreased it in T98G cells. siRNA blockade of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) expression partially reversed VPA-mediated effects in T98G cells, but had no effect on A172 cells. VPA increased the expression of phospho-JNK1 and phospho-ERK1/2 in A172 cells, but decreased it in T98G cells. Inhibition of JNK1 and/or ERK1/2 partially reversed the VPA effects in A172 cells. In conclusion, the effects of VPA (loss of viability, increased apoptosis, and decreased invasiveness) are, at least partly, mediated through the RECK-MMPs pathway in T98G cells and the mitogen-activated protein kinase pathways in A172 cells. The action of VPA seems to be cell type-specific in glioma cells.

Lecture: profile of risks and benefits of new antiepileptic drugs in brain tumor-related epilepsy

In patients with brain tumor, seizures are the onset symptom in 20-40% of the patients, while a further 20-45% of the patients will present them during the course of the disease. These data are important when considering the choice of antiepileptic drugs for this particular patient population, because brain tumor-related epilepsy (BTRE) is often drug resistant, has a strong impact on the quality of life and weighs heavily on public health expenditures. In brain tumor patients, the presence of epilepsy is considered as the most important risk factor for long-term disability. For this reason, the problem of the proper administration of medications and their potential side effects is of great importance, because good seizure control can significantly improve the patient's psychological and relational sphere. In these patients, new generation drugs such as gabapentin, lamotrigine, levetiracetam, oxcarbazepine, pregabalin, topiramate, and zonisamide are preferred, because they have fewer drug interactions and cause fewer side effects. Among the recently marketed drugs, lacosamide has demonstrated promising results and should be considered as a possible treatment option. Therefore, it is necessary to develop a customized treatment plan for each patient with BTRE, whose goals are complete seizure control, minimal or no side effects, and elimination of cognitive impairment and/or psychosocial problems.

Impact of antiepileptic drugs on thrombocytopenia in glioblastoma patients treated with standard chemoradiotherapy

Epilepsy in glioblastoma multiforme (GBM) patients is common. Hematological toxicity is a potential side effect of antiepileptic drugs (AEDs) and a frequent limiting-dose effect of temozolomide (TMZ). The aim of the study was to investigate the impact of AEDs on thrombocytopenia in GBM patients treated with radiotherapy and TMZ. A cohort of 101 newly diagnosed GBM patients treated with radiotherapy and TMZ was reviewed. Clinical data, presence of seizures, AEDs use, platelet count, and accumulated TMZ dose were analyzed at each cycle. Thrombocytopenia was operationalized as a continuous platelet count and a dichotomic variable (cut-off <100.000/mm(3)). This cut-off represents the threshold beyond which TMZ treatment is modified. A linear and a probit pooled cross-sectional regression analysis were used to study the impact of age, gender, AEDs, and accumulated TMZ on thrombocytopenia. Impact of AEDs on survival was also analyzed. Thirty-five patients (35%) presented seizures at onset and 18 (27%) during follow-up. Seven (13%) needed two or more AEDs for seizure control. Grade 3-4 thrombocytopenia was found in 8%. Decrease in platelet count was related to accumulated TMZ (p < 0.001), age (p < 0.001), and valproate (p = 0.004). Platelet count <100.000/mm(3) was only associated with accumulated TMZ (p = 0.001). Recursive Partitioning Analysis prognostic class was the only variable with significant impact on survival. Valproate and age had an independent negative effect on total platelet count, although neither had an effect on critical thrombocytopenia (<100.000/mm(3)). Therefore, the systematic withhold of valproate in GBM patients might not be justified. Nevertheless, this negative effect may be taken into account especially in elderly patients.