Ketogenic diet treatment in diffuse intrinsic pontine glioma in children: Retrospective analysis of feasibility, safety, and survival data

Current knowledges in pharmaconutrition: "Ketogenics" in pediatric gliomas

Brain tumors account for 20-25% of pediatric cancers. The most frequent type of brain tumor is Glioma from grade I to grade IV according to the rate of malignancy. Current treatments for gliomas use chemotherapy, radiotherapy, tyrosine kinase inhibitors, monoclonal antibodies and surgery, but each of the treatment strategies has several serious side effects. Therefore, to improve treatment efficacy, it is necessary to tailor therapies to patient and tumor characteristics, using appropriate molecular targets. An increasingly popular strategy is pharmaconutrition, which combines a tailored pharmacological treatment with a diet designed to synergize the effects of drugs. In this review we deal in the molecular mechanisms, the epigenetic effects and modulation of the oxidative stress pathway of ketogenic diets, that underlie its possible role, in the treatment of infantile gliomas, as a complementary approach to conventional cancer therapy.

Interdisciplinary care of children with diffuse midline glioma

Diffuse Midline Glioma (DMG) which includes Diffuse Intrinsic Pontine Glioma (DIPG) is an infiltrative tumor of the midline structures of the central nervous system that demonstrates an aggressive pattern of growth and has no known curative treatment. As these tumors progress, children experience ongoing neurological decline including inability to ambulate, swallow and communicate effectively. We propose that optimal care for patients with DMG should involve a specialized team experienced in caring for the multifaceted needs of these patients and their families. Herein we review the roles and evidence to support early involvement of a specialized interdisciplinary team and outline our views on best practices for these challenging tumors.

Ketogenic Diet in the Treatment of Gliomas and Glioblastomas

In recent years, scientific interest in the use of the ketogenic diet (KD) as a complementary approach to the standard cancer therapy has grown, in particular against those of the central nervous system (CNS). In metabolic terms, there are the following differences between healthy and neoplastic cells: neoplastic cells divert their metabolism to anaerobic glycolysis (Warburg effect), they alter the normal mitochondrial functioning, and they use mainly certain amino acids for their own metabolic needs, to gain an advantage over healthy cells and to lead to a pro-oncogenetic effect. Several works in literature speculate which are the molecular targets of KD used against cancer. The following different mechanisms of action will be explored in this review: metabolic, inflammatory, oncogenic and oncosuppressive, ROS, and epigenetic modulation. Preclinical and clinical studies on the use of KD in CNS tumors have also increased in recent years. An interesting hypothesis emerged from the studies about the possible use of a ketogenic diet as a combination therapy along with chemotherapy (CT) and radiotherapy (RT) for the treatment of cancer. Currently, however, clinical data are still very limited but encouraging, so we need further studies to definitively validate or disprove the role of KD in fighting against cancer.

The efficacy of an unrestricted cycling ketogenic diet in preclinical models of IDH wild-type and IDH mutant glioma

Infiltrative gliomas are the most common neoplasms arising in the brain, and remain largely incurable despite decades of research. A subset of these gliomas contains mutations in isocitrate dehydrogenase 1 (IDH1^mut) or, less commonly, IDH2 (together called “IDH^mut”). These mutations alter cellular biochemistry, and IDH^mut gliomas are generally less aggressive than IDH wild-type (IDH^wt) gliomas. Some preclinical studies and clinical trials have suggested that various forms of a ketogenic diet (KD), characterized by low-carbohydrate and high-fat content, may be beneficial in slowing glioma progression. However, adherence to a strict KD is difficult, and not all studies have shown promising results. Furthermore, no study has yet addressed whether IDH^mut gliomas might be more sensitive to KD. The aim of the current study was to compare the effects of a unrestricted, cycling KD (weekly alternating between KD and standard diet) in preclinical models of IDH^wt versus IDH^mut gliomas. In vitro, simulating KD by treatment with the ketone body β-hydroxybutyrate had no effect on the proliferation of patient-derived IDH^wt or IDH^mut glioma cells, either in low or normal glucose conditions. Likewise, an unrestricted, cycling KD had no effect on the in vivo growth of patient-derived IDH^wt or IDH^mut gliomas, even though the cycling KD did result in persistently elevated circulating ketones. Furthermore, this KD conferred no survival benefit in mice engrafted with Sleeping-Beauty transposase-engineered IDH^mut or IDH^wt glioma. These data suggest that neither IDH^wt nor IDH^mut gliomas are particularly responsive to an unrestricted, cycling form of KD.

Effects of the Ketogenic Diet in the Treatment of Gliomas: A Systematic Review

The ketogenic diet (KD) is a restrictive therapeutic diet, distinguished by being hyperlipidic, normoproteic, and hypoglucidic. This diet simulates biochemical changes related to fasting periods to achieve systemic ketosis. The metabolic particularities of glioma tumors motivated the rise in investigations and nutritional strategies, such as KD, to modulate the glycemic response as a treatment. This systematic review followed the PRISMA recommendations and was published in PROSPERO, with the identification CRD42021264173. The databases used were EMBASE, PubMed/Medline, Scopus, and Web of Science, and the studies were analyzed using the web-based application Rayyan. To analyze the risk of bias, Cochrane RevMan 5 software was used. For the analysis and treatment of statistical data, Microsoft® Excel® was used. A total of nine original articles were included. Data on survival, symptomology, and quality of life were collected. Mean overall survival was 15.9 months. Constipation and fatigue were the most reported symptoms. In 44.4% of the studies, an improvement in the quality of life was found. The KD is supported by most published studies as an effective therapy in the treatment of malignant gliomas due to its positive effects on patient survival. It was not possible to conclude the effectiveness of KD on quality of life.