How likely can you get breast cancer if you have a family history?

Varies: Mutated brca1 and brca2 if inherited give you a very high lifetime chance for getting breast cancer, especially if you are a woman, but also applies to men. Beyond this, having a relative who's had it increases the risk somewhat, the more relatives and the closer the relationships the greater, but it's not striking. Simply keep up the usual watch for the disease and when caught early, cure's usual.