"Should a woman have a preventive mastectomy if her lifetime breast cancer risk is 25 percent compared to the average woman’s risk of 12 percent?" The risk percentage of breast cancer by mutations of the known genes BRCA1 and BRCA2 were high enough, one would say, to make informed choices of whether to undergo mastectomy. There are now new mutations that are not as high and make choices tough for women. Read about the study.
