Given that cancer cells are fueled by glucose (i.e., sugar metabolism), you might read up a bit on carb-restricted diets:

http://www.proteinpower.com/drmike/ketones-and-ketosis/carbo...

"Since cancers can't really get nourishment from anything but glucose, it stands to reason that cutting off this supply would, at the very least, slow down tumor growth, especially in aggressive, fast-growing cancers requiring a lot of glucose to fuel their rapid growth. Thomas Seyfried [showed] that ketogenic diets in animals and humans can stop malignant brain tumors."