Tumor Treating Fields for Glioblastoma Multiforme: Effectiveness and Safety

Glioblastoma multifome (GBM) is the most common and most lethal primary brain tumor in adults. The standard treatment for GBM with good performance is maximal surgical resection followed by adjuvant chemoradiotherapy and adjuvant temozolomide therapy. In addition to this treatment, alternating electric fields or tumor treating fields (TTFields) are also recommended at category 1 level in the NCCN guidelines. In this review, the mechanism of action of alternating electric fields therapy in GBM, its efficacy in GBM and expected side effects will be discussed. TTFields is a treatment modality that acts on dividing cells by generating therapeutic levels of electric fields. Causing DNA damage and inhibiting DNA repair, activating apoptosis, autophagy and immunogenic death pathways, causing destruction of the cytoskeleton network, causing the formation of pores in the membrane and causing cellular destruction by disrupting cellular ion balance are the effects of alternating electric field therapy on cells. TTFields, which has also been tested in tumors such as lung cancer, pancreatic cancer and malignant mesothelioma, has proven to be a survival-enhancing treatment in primary and recurrent GBM patients. The risk of serious toxicity was found to be very low and the most common side effects were mild and moderate dermatologic toxicities. Having proven its efficacy and safety in GBM patients, TTFields is likely to benefit many more patients if cost issues can be overcome.

Keywords: GBM; toxicity; tumor treating fields.