The four causes of disease if you wish to label cancer as a disease. They are found in Kevin Trudeau's books. Toxins and nutritional deficiencies contribute to the development of cancer. Looking at this in the form of analogies, the body lacks the right tools to deal with the problem when it comes to nutritional deficiencies. Toxins can be like the spark that ignites the fire.
Remember what the Center of Disease Control stated. Now think of what emotions are. Emotions are forms of energy. Everything has some type of energy frequency. There is a broad spectrum of energies that exist. The trick is to find the right type of energies in order to treat the problem.