I don't like my partners female best friends

My boyfriend has this girl he's extremely close. He tells her everything. They've been friends 9 years. I tried to like her. But she is so... ANNOYING. She talks so damn much. She also does weird things that aren't bad. Just socially unacceptable. Like she called our college professor (we had one class together last year) by her first name. She's been told she talks too much and oh my fucking God if I hear "I had cancer" one more time I'm gonna lose it. She has cancer when she was 15 and she will talk about it 1859 times. She has cancer 13 years ago. Why are we still hearing about it? She's never done anything to me or shady. She's just annoying and I'm not sure what to do about it