It turns out that what happens to a cancer cell depends a lot on what you feed it. Using laboratory animals with cancer, T. Colin Campbell was able to make tumors appear and disappear simply by changing the amount of cows' milk protein in the diet. His book, "The China Study" (http://www.thechinastudy.com/ ) provides a wealth of information on this and other findings relating diet and disease.
Another good resource is The Cancer Project, (http://www.cancerproject.org/) which aims to make nutrition research findings accessible to cancer patients. Besides a detailed website, the Cancer Project offers cooking classes all over the country, open to patients, their caregivers, and anyone else who is interested in healthy eating.