preventive masectomy

can anybody tell me about preventive masectomy? When I lost my breast in 1995 i had a cyst on my right it is still there today, a lot of my family has read on this surgery that with my history of breast disease because I always have boils & cyst all the time on this breast, one Doctor recommends me to have it .I'm 6yrs cancer -free & I don't know what to do because from the chemeo when I had cancer it mess up my lungs I have asthma along with c.o.p.d. which I'm scared to have surgery unless its a necessity. My family is more scared than I am. I just give it to the Lord & let him make the decision for me , so if anybody out there knows anything about this surgery with the pro's & con's also about it I woulsd love to know thank-you CHERYL