UCSF mentions the age factor in their section on Bc risk, Part of it reads:
"You may have heard the statistic that one in eight women in the United States will develop breast cancer. This does not mean that a woman of any age has a one-in-eight chance of developing breast cancer. This statistic conveys a woman's lifetime risk. This means that if a woman lives until age 85, she has a risk of one in eight of developing breast cancer sometime during her lifetime."
I don't know if their clarification comforts me or not. Anyway, I'm in the group they say has the most diagnoses, so I'd better keep up my morning reclining exercises, my standing exercises, and the exhausting hunt for shoes that make my feet painless on longer walks.
I am not enthusiastic about all their links to other sites, but there is plenty of other interesting information on their site.
I wish you health.