Cancer research is, unfortunately, an inefficient process. 90% of good ideas turn out to be busts (and that is an optimistic estimate). All cancer treatments have side effects, sometimes fatal. It all comes down to a balance between risk and benefit. There are some cancers, including the worst pediatric brain tumors, that are nearly always lethal. There are thousands of smart, dedicated, caring researchers who spend their entire careers slugging it out against this opponent, and many don't get very far.
The lack of success is not for lack of trying, or because of an elaborate conspiracy. Cancers are frequently hard to cure.
My advice to anyone with cancer is to ask their doctor who they would send their own family members to, and ask for a referral to that person. Request a second opinion from a respected research center (like St. Jude). The LAST thing I would do is grasp at the false hope offered by junk science.