Hi Janey, 2 years ago I made the decision to have a prophylactic mastectomy at the time of reconstruction with tissue expanders and then implants. Like Viv, my cancer was diagnosed by ultrasound after 2 clear mammograms 3 months apart. Even the doctors couldn't feel the 4mm tumour. Pathology showed a 21mm grade 3 invasive ductal cancer. My surgeon always said he would happily take off the other breast if I wanted, as even he was concerned that we might never be sure that there wasn't something else lurking there. Anyway an MRI showed nothing more, so due to it being Christmas, and a huge decision, I just had a single mastectomy following the lumpectomy, and went and did chemo and gave my body time to heal. 9 months later I chose to have the other one off at the time of reconstruction. A final check up before the surgery with a mammogram and ultrasound again showed a clear mammo with a highly suspicious lump on ultrasound. I was devastated and had to wait again for core biopsy results. Luckily this time the results showed nothing cancerous, but for me it was a clear sign that I was doing the right thing. I have never ever regretted this decision. It has given me peace of mind. This is a huge decision, and for me, making it was the hardest part. Once I had decided, it became easier. I knew, that I would be really annoyed with myself if I got cancer in the other breast and could have avoided it. We are all different, and only you can know what the best thing for you will be. Good luck with your decision making. Love Chris xx