A Low-Carbohydrate Diet for Advanced or Metastatic Cancer

In their natural state within the body, cells normally depend on cellular respiration as the source of energy and ATP. During times of complete or partial food deprivation these cells can also rely on ketosis as an additional energy source. Tumor cells in contrast are defective in this respect, lacking in the ability to utilize ketone bodies for energy and instead are heavily dependent on glycolysis for their survival. Malignant cells depend heavily on glycolysis for energy production even in high oxygen states. If the investigators limit the supply of glucose, glycolysis would decrease and tumor cells would lose their main source of energy supply.

In addition, increased carbohydrate intake is sensed by the pancreas and results in increased insulin secretion. Insulin is important for normal growth in the body and is a potent growth factor stimulating mitosis via signal transduction and DNA synthesis. It is a potent growth factor which acts by binding to cell membrane insulin receptors and stimulates mitosis via protein kinase B/Akt- mediated signal transduction and DNA synthesis.

Insulin also has anti-apoptotic properties, meaning less tumor cell death. Increased circulating insulin levels have been associated with increasing risk of certain cancers (i.e. prostate and colon cancer), but no association with serum glucose levels (8). By limiting carbohydrate intake, the investigators might expect decreased tumor growth and increased tumor cell destruction.

Most human and mouse tumors take up more glucose than their surrounding normal tissue. By using positron emission tomography with fluoro-deoxy-glucose, FDG-PET scans can be used to detect and monitor tumor response to chemotherapy and radiation.

In this study, PET/CT scanning would be utilized to measure the amount of (at the screening visit) glucose activity within certain tumors, before and after the diet.