I believe that if a person really makes the effort to live and eat healthily, including removal and avoidance of toxins and stress, then cancer is up to 90% or more preventable. I likewise believe that cancer is 90% or more beatable even if you do get it.
Where I would differ is the concept that inherited mutations are the cause of any large percentage of cancers. With rare exception, we are not born with cancer. In the vast majority of instances inherited mutations which have been linked to cancer merely mean that a person may be more likely to develop cancer. Along with tobacco and radiation, It still comes down to cellular terrain and toxins (and I consider tobacco and radiation to be toxins). Properly nourished, cleansed and hydrated cells are very unlikely to develop cancer regardless of inherited mutations..