THE EFFECT OF KETOGENIC DIET ON SURVIVAL AND QUALITY OF LIFE IN PATIENTS WITH MALIGNANT BRAIN TUMORS IN PALLIATIVE CARE

BACKGROUND: The cure for malignant brain tumors such as glioblastoma is never achieved. The patients could not survive so long time to spend the useful life after quitting the multimodal aggressive therapies and choosing the palliative care. The metabolism of tumor cells manifests abnormal accentuation of aerobic glycolysis regardless of oxygen concentration, resulting in increased consumption of glucose with production of large amounts of lactate for proliferation as well known as the ‘Warburg effect’. Ketogenic diet (KD) is a low-carbohydrate and high-fat diet, resulting in reduction of serum glucose level and induction of a large amount of ketone bodies. Under the KD the normal cells are able to obtain the energy from ketones, while tumor cells are not because lacking mitochondrial ketolytic enzymes. Therefore the KD restricting glucose is supposed to selectively starve tumor cells and inhibit tumor growth. Objective: The purpose of this study is to investigate if the KD offers useful life to patients with malignant brain tumors in palliative care. METHODS: Written informed consent was obtained from the patients or patient’s family. KD treatment was conducted under our protocol approved by the Research Ethics Committee of the Institutional Review Board of Kumamoto University Hospital. Results: Two patients with malignant brain tumors in palliative care underwent KD. The first case is a 3-year-old boy with anaplastic ependymoma. Despite of radio-chemotherapy, the uncontrolled tumor progression was found and palliative care with KD started. Surprisingly he had been still well without any major adverse event and no disease progression was observed until 13 months later from starting palliative care with KD alone. He could spend the happy time with his parents at his home and could survive for 32 months from the date of diagnosis. The other is a 37-year-old man with glioblastoma who underwent radio-chemotherapy. However the disease had progressed 3 months later from diagnosis and palliative care with KD started. Surprisingly MRI on 8 months from starting KD revealed no contrast-enhanced lesions. He had no major side effect and could survive for 20 months from the date of diagnosis. Conclusions: KD may offer the additional survival time with acceptable quality of life to patients with malignant brain tumors in palliative care.