Unfortunately, it has been found that cancer tends to be genetically heterogeneous even within the same tumor. A treatments may kill off one cell line and thereby slow a tumor, but also spare other lines that then begin to multiply with renewed vigor.
All cells have a suicide mechanism called "apoptosis." This mechanism is activated whenever a cell undergoes serious damage. One of the problems in cancer is that the cancer cells often lose or disable that mechanism. With many kinds of cancer treatments designed to activate apoptosis, loss of this causes cancers to fail to respond to therapy. A treatment that would restore apoptosis in the method described in the full article at the link might not directly kill cancers, but it would restore susceptibility to therapy.
While it is true that cancers have considerable genetic heterogeneity, there are certain features that are common to many cancers. Being able to target one of these features would be a great step forward.
Researchers are testing anti-cancer drug cocktails to deal with this problem. Two or three drugs attacking the cancer cells in different ways. Same approach as is used with AIDS treatment.
http://www.earthclinic.com/CURES/cancer.html
There has been some tremendous advances made using ‘unapproved’ techniques in curing cancers. The medical industry hates these cures because there is absolutely no money to be made from them. Most folks are too afraid to try them until they get to stage four and there’s nothing else for them to grab onto.