What would you like to know about preventative mastectomies? I've just had a double mastectomy after a tumour in one. Technically having that breast removed was called completion, and a good job too because they found more DCIS. The other breast was described as prophylactic. I have a bad family history, dense breasts, and a proclivity to occult cells (bad cells that can't be seen by scans). There were a number of other reasons. I am comfortable with my decision, so far anyway, it was less than four weeks ago, but it has not been and is not easy.