My then GF found a lump back in 2005, she was seen within a week and ultimately had surgery to remove the breast, chemotherapy and reconstructive surgery.
It was hard for her, but she came through it and says herself 10years on it changed her life but ironically in a positive manner.
As I say, this was 10years ago, I recall her being told then how treatment had improved and she was lucky it had, hers was an aggressive one.
My point being, assuming it's worst case which is by no means a given, she got on just fine 10years ago, today with the further advances in treatment,your Mrs will too.
Don't study the web endlessly, support her and be there for her.