Perhaps a good reason to abstain, at least temporarily and frequently. My wife's first friend passed away after 3 separate and unrelated bouts of breast cancer (another form, or two concurrently, is what ultimately killed her). Family history of BRCA-1 which doesn't cause cancer but makes you more susceptible if the gene that prevents mutations goes faulty (those with BRCA1 and/r BRCA-2 already have one faulty gene so have only one good one to rely on, vs. those who don't have either gene and have 2 good copies).