It is said that Cancer can't exist in alkaline environment, I agree. My point was that during a fast a mineral imbalance brought by man-added minerals can disturb the coping mechanisms of the faster, not exactly acidity or alkalinity.
There is a doctor in Boston who brings his patients to alkaline urine and saliva (to pH 9 and above, if I remember, over extended time) to successfully reduce or heal their cancers. He is on youtube too, I don't remember his name, though. He works with juices, alkaline food and water.