Antiepileptikabehandlung bei Hirntumor-bedingten epileptischen Anfällen

Combination of levetiracetam and IFN-α increased temozolomide efficacy in MGMT-positive glioma

PURPOSE

Glioma, especially glioblastoma (GBM), is the most aggressive malignant brain tumor and its standard therapy is often ineffective because of temozolomide (TMZ) resistance. Reversal of the TMZ resistance might improve the prognosis of glioma patients. We previously found that interferon-α (IFN-α) and anti-epileptic drug levetiracetam (LEV) could sensitize glioma to TMZ, respectively. In this study, we further investigated the efficiency of combining of LEV and IFN-α for improving the efficacy of TMZ.

METHODS

We evaluated whether LEV and IFN-α could increase TMZ efficacy using colony formation assay and cell viability assay with MGMT-positive and MGMT-negative glioma cell lines in vitro. Subcutaneous xenografts and orthotopic xenografts mice models were used in vivo to observe the tumor growth and mice survival upon treatments with TMZ, TMZ + IFN-α, TMZ + LEV, or TMZ + LEV + IFN-α. The expression levels of MGMT, markers of pro-apoptotic and anti-apoptotic in tumor samples were analyzed by Western blotting.

RESULTS

The combinational use of IFN-α, LEV, and TMZ showed the best anti-tumor activity in MGMT-positive cell lines (U138, GSC-1, U118, and T98 G). TMZ + LEV + IFN-α further obviously increased TMZ + LEV or TMZ + IFN-α efficiency in MGMT-positive cell lines, while not in negative cell lines (SKMG-4, U87, U373, and U251) in vitro, which were also observed in subcutaneous mice models (U138, GSC-1 compared to SKMG-4, U87) and orthotopic models (GSC-1) in vivo. Strikingly, the combination of LEV and IFN-α together with TMZ significantly prolonged the survival of mice with orthotopic GSC-1 glioma. Furthermore, we confirmed that the combination of LEV and IFN-α enhanced the inhibition of MGMT and the activation of apoptosis in U138 tumor on the basis of TMZ treatment.

CONCLUSIONS

The combination use of LEV and IFN-α could be an optimal method to overcome TMZ resistance through obvious MGMT inhibition in MGMT-positive glioma.

Antiepileptic Drugs in the Management of Cerebral Metastases

Seizures represent a common and debilitating complication of central nervous system metastases. The use of prophylactic antiepileptic drugs (AEDs) in the preoperative period remains controversial, but the preponderance of evidence suggests that it is not helpful in preventing seizure and instead poses a significant risk of adverse events. Studies of postoperative seizure prophylaxis have not shown substantial benefit, but this practice remains widespread. Careful analysis of the risk of seizure based on patient-specific factors, such as tumor location and primary tumor histology, should guide the physician's decision on the initiation and cessation of prophylactic AED therapy.

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.