I think the cancer is related to emotion of the individual like as your explained. I had been read this literature about the problem, and the result is cancer positive gained by negative emotion.

in other literature, cancer wil be cause of the radical cosmic ray through our earth atmosfer. the radical ray can change the chemical reaction in body tissue for produce toxic compound for cell metabolic. in this case, the chemical reaction is very sensitive to light, so when the wavelengh of electromagnetic radiation changed, it can change the chemical reaction occur and produce the cancer cell.

of the light concept, the saintis had been developed the radioterapy methode for healing the cancer cell.

I am sorry about my english is not good(--)