Connie,
there's lots of articles on popping pills or eating fresh,
it's another chicken & egg issue,
no one has a definite reply.
Many reasons cause cancer,
my own dad is a cancer survivor, twice some more.
When I when National Cancer Center with him,
(as usual, KPO me will talk to people lah)
most patients there are struck when they least expect the tumor.
Doctor says genes, air, food, water, habits, lack of sleep, stress lifestyle, etc, etc, etc...
How to explain?
Just my 2 cents.