Plenty of “healthy” people die of cancer. My sister in law passed away at 49. She had no family history of cancer, ate healthy, ran daily, was not overweight for her entire life.
My mother, sister, brother, father, multiple aunts and grandmother have had it one or more times.
I've had it zero times.
Thus diet and exercise are also not reasonable substitutes for researching better treatments for those who do get cancer.
I'm trying to step away from this discussion. It is kind of off topic and I don't think it's productive.