I wouldn't say plenty, but you can drastically improve your odds if you don't smoke, drink, and eat healthy. But even if you do all those things some cancers are like getting struck by lightning.
I believe many cancers can be cured with a alkaline diet and other things. Chemo is poison.
Agree with you to an extent. If you have tpoor genes, but if you are disappointed enough to eat a pure plant based diet you odds of stroke, heart disease, cancers are drastically reduced. Hell, pure plant base can reverse plaque in the arteries.