We have been told everyone has dormant cancer cells and something in the environment triggers it.
A steady healthy immune system, natural food and water grown in healthy soil, animals raised naturally and organically, and a decent caring 5* Doctor helps prevent a lot of diseases and problems before they happen or get out of control. I am talking from birth to adult and old age with no deviations in diet and how the vegetables, fruit, animals are raised for food.
But then there are some that will get cancer no matter what. I think it has to do with the genetic immune system, but that is my unresearched thought so far. J.