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.
Another devastating side effect of chemotherapy is the way it actually supports the more chemo resistant and malignant cell subpopulations within tumors (e.g. cancer stem cells), both killing the more benign cells and/or senescent cells within the tumor that keep it slow-growing, or even harmless.
As a result, this unleashes a more aggressive, treatment-resistant type of cancer to wreak havoc on the body.