I have not been following this thread so apologies if I seem to be off base, however in casual study of this issue, and given some of the recent information coming out of china in industrialized, hi polluted cities, I firmly believe that our polluted environment contributes more to these cancers than our indulgences. In fact their are several cancers named for and directly associated with certain professions.
I suspect though that the incidence of cancers are exacerbated by our indulgences though.