@Anne65 I think they would only revisit if another family member popped up with cancer. But keep reading about breast cancer and when a new gene is identified you can contact them and discuss if it's worth checking for it.
As to the gene...it's a lotto. I can't tell you how happy I was to find both my full blood brother and sister where gene negative too...which probably means my Dad didn't inherited the faulty BRAC1 gene. The relief that my children and my niece and her children were safe in that respect brought tears. It meant we could just move on without fear and just keep being vigilent with out health.
Your results letter will list which genes were checked so store somewhere safe and you can recheck which ones you were checked for .