In the fight against cancer, stimulation of both the innate and the adaptive branches of the immune system is helpful, but we may need a bit more killing. Accordingly, a wise person would try to find many substances, each of no more than moderate toxicity, that do not target the same system and that cancer cells are considerably more sensitive to.
Chemotherapeutic agents are way off the mark – they are highly toxic and they target the same system, the reproduction of cells. While most of the non-cancerous cells in the body are non-growing, there are important populations of normal cells that need to grow and reproduce to maintain our health.
This is yet another instance of the inferiority of the pharmaceutical approach, high concentrations of the single magic bullet, vs the natural approach, lower concentrations of a network of substances, each with higher S/N.