One of the reasons why conventional cancer treatment is such a dismal failure in the United States is because it relies on chemotherapy.
Chemotherapy drugs are, by their very nature, extremely toxic and typically work against your body's natural ability to fight cancer, e.g. destroying host immunity instead of supporting it.
One of the biggest drawbacks to chemotherapy is the fact that it destroys healthy cells throughout your body right along with cancer cells, a "side effect" that often leads to accelerated death, not healing.