title: Tumor Metabolism, the Ketogenic Diet and β-Hydroxybutyrate: Novel Approaches to Adjuvant Brain Tumor Therapy.
abstract: Malignant brain tumors are devastating despite aggressive treatments such as surgical resection, chemotherapy and radiation therapy. The average life expectancy of patients with newly diagnosed glioblastoma is approximately ~18 months. It is clear that increased survival of brain tumor patients requires the design of new therapeutic modalities, especially those that enhance currently available treatments and/or limit tumor growth. One novel therapeutic arena is the metabolic dysregulation that results in an increased need for glucose in tumor cells. This phenomenon suggests that a reduction in tumor growth could be achieved by decreasing glucose availability, which can be accomplished through pharmacological means or through the use of a high-fat, low-carbohydrate ketogenic diet (KD). The KD, as the name implies, also provides increased blood ketones to support the energy needs of normal tissues. Preclinical work from a number of laboratories has shown that the KD does indeed reduce tumor growthin vivo. In addition, the KD has been shown to reduce angiogenesis, inflammation, peri-tumoral edema, migration and invasion. Furthermore, this diet can enhance the activity of radiation and chemotherapy in a mouse model of glioma, thus increasing survival. Additional studiesin vitrohave indicated that increasing ketones such as β-hydroxybutyrate (βHB) in the absence of glucose reduction can also inhibit cell growth and potentiate the effects of chemotherapy and radiation. Thus, while we are only beginning to understand the pluripotent mechanisms through which the KD affects tumor growth and response to conventional therapies, the emerging data provide strong support for the use of a KD in the treatment of malignant gliomas. This has led to a limited number of clinical trials investigating the use of a KD in patients with primary and recurrent glioma.
authors.affiliation: Neuro-Oncology Research, Barrow Brain Tumor Research Center, Barrow Neurological Institute, St. Joseph's Hospital and Medical CenterPhoenix, AZ, USA; School of Life Sciences, Arizona State UniversityTempe, AZ, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Woolf
authors.affiliation: The John Fulcher Molecular Neuro-Oncology Laboratory, Division of Brain Sciences, Imperial College London London, UK.
authors.forename: Nelofer
authors.initials: N
authors.lastname: Syed
authors.affiliation: Neuro-Oncology Research, Barrow Brain Tumor Research Center, Barrow Neurological Institute, St. Joseph's Hospital and Medical CenterPhoenix, AZ, USA; School of Life Sciences, Arizona State UniversityTempe, AZ, USA.
authors.forename: Adrienne C
authors.initials: AC
authors.lastname: Scheck
keywords: beta-hydroxybutyrate; cancer; glioblastoma; glioma; ketogenic diet; ketones; metabolism