Mort Divine
Shrine Maiden of the In-Crowd
Cancer isn't a foreign organism. It's not a cold or flu bug you can attack or defend against with immune system boosters. It's your own cells "going rogue", due to damage of some kind.
Cancer (especially of the liver, a filter) suggests either not enough correct nutrition to keep the cells healthy, or too much "poison", or both.
Poison in which context? I think a lot of people who mention this in regards to cancer tend to focus only on the food/smoking/drinking aspects of poisons and completely underplay environmental aspects that can be majorly important as well.