Craigakess - Carrying the BRCA gene makes someone a strong candidate to get breast and ovarian cancers later in life. Plenty of women in this situation indeed opt for preventative mastectomies to run down their risk for later development.
For instance: Angelina Jolie did so in 2014:
https://www.cnn.com/2013/05/14/showbiz/angeli...index.html