I was told that having it on one side increases your risk of developing it on the other side, and I would have had to do mammograms every six months and possibly take Tamoxifen for five years if I left the right side untouched. I also took symmetry into consideration. It was the right choice for me and gave me more peace of mind, but I realize some people do choose single mastectomy. The doctor also mentioned that they would be on high alert for suspicious findings in the left breast if I left, it untouched, and I would likely have more biopsies than the “normal person.”