I was diagnosed with DCIS 1A in left breast, the surgeon advised me that due to being localized lumpectomy was the best road because of shorter recovery period and same outcome with mastectomy. I did radiation after lympectomy and my margines were clear, my lymphnodes were clear. I did not do chemo, but I am doing Lupron with Letrozole. I started feeling something weird on my right breast and long story short it was just fibroadenoma. But, at that time I questioned myself for nor just have both breast taken out for a peace of mind. But, I had also read women who have had mastectomy and had the cancer come back. So I think that if I were you I would listen to my body, what is your body telling you? Also if it is not localize and you have more than one spot then maybe is best to go with everything. In my case if this cancer returns I will go with everything mastectomy and chemo. I pray you make the right decision for you and remember always listen to your body it will tell you what is the right thing to do.