I have no experience with MMS and brain tumours but did work with a young man many years ago who had been given only a few months to live. He has been through the full spectrum of surgery and chemo. The cancer had returned and he had several small new tumours. They could not operate any more given the location of the growths.
He came to see me as, at that stage, I was practicing a form of therapy that deals with the subconscious mind and someone he knew had recommended that he have a chat with me.
To cut a long story short, this beautiful young man considered himself a failure and that life was not worth living. He had a very hard man for a father who never praised him or found anything to be positive about and was violent physically, mentally and spiritually. This young fellow went to the USA and was runner-up world champion in a sport that he was involved in only to win his father's approval - it was not his passion.
Upon returning to Australia after his success his father spat on the ground and asked him if that was the best he could do - he may as well have been last as second best was second rate.
We did some work together around letting go of the need to have his father's approval and handing back all the "disappointment" he had been to his father - this was done of course in the mind. He wrote letters to his father telling him how he had felt like a failure all of his life and that no-one could ever love him. There were many tears and a ceremonial burning of the letters and he let his need for approval float away with the smoke.
After this, the young man could actually look on his father and see him for the damaged person that he was and feel compassion for him - it was almost as if he became the father figure and his father the child in need of healing.
He cured himself of cancer - it simply disappeared from his life.
The relevance of this is that, in my experience so far, hanging on to such incredibly debilitating beliefs predisposes us to many health problems so it may well benefit your friend to find a Bridging therapist and clear any such beliefs so that his emotional energy can also be directed towards health.
Far away there in the sunshine are my highest aspirations. I may not reach them, but I can look up and see their beauty, believe in them, and try to follow where they lead.
Louisa May Alcott