Dry fasting or Water Fasting are in my opinion very dangerous to do for a cancer patient. You need good nutrition in order to fight cancer. I believe cancer is very linked to candida and/or parasites, and a water or dry fast just won't touch them. Also, any proven therapy will place a great stress on the liver, as toxins from cancer cells or dead microbes are released. Juice-fasting with the proper juices is in my opinion far more beneficial for that matter.