Currently used cancer treatment options vary from surgery, chemotherapy, radiation, to many other therapies. Chemotherapy involves the use of drugs to destroy cancer cells, but can also harm perfectly healthy cells, causing side effects throughout the body. Fasting in combination with chemotherapy has already been shown to kill cancer cells more efficiently than chemotherapy alone. Researchers have now discovered that fasting combined with a less-toxic class of drugs, kinase inhibitors, may starve cancer cells to death so effectively that the new treatment may one day replace chemotherapy.
Cancer cells rely heavily on glucose (sugar) from food for energy. They are on overdrive, burning much more glucose than a regular cell to fuel their rapid growth. This phenomenon is called the 'Warburg effect', which is named after the German physician who first described it nearly 100 years ago. The study pointed out that deprived of glucose, cancer cells rely on an emergency backup, using a type of enzyme called kinase to continue their growth-related activities.
Researchers discovered that this metabolic shift by cancer cells causes them to generate toxic-free radicals, which ultimately kills them. The researchers noted that with the help of kinase inhibitor drugs, cancer cells' ability to generate energy can be further choked. Kinase inhibitors are already approved by the US Food and Drug Administration (FDA) as a cancer treatment option, opening the door to using them and fasting as a new therapy to knock out cancer.
Valter Longo, senior author from University of Southern California Davis School of Gerontology, said, "If shown to work in humans, this combination could replace chemotherapy and make fasting a potent component of a long-term strategy to treat cancer. Like every other cell, cancer cells need energy to survive and keep growing. But cancer cells are fairly inflexible about how they produce that energy, which gives us a way to target them. Kinase inhibitors, though much less toxic than chemotherapy, can still be toxic to many cell types. Fasting makes them more effective, meaning that patients would have to use them for less time to achieve the same results."
The study is published in Oncotarget.