I was diagnosed in 2007 at 36 and had a Left mastecomy (because of the size 27mm) and ancillary clearance at the same time. I had a sentinel node removed and it looked a bit suss, so they opted to take 16 nodes (ancillary clearance). I only had one node affected but they removed the lot anyway.
Earlier this year I had my other breast removed and reconstruction on both. I have not had a reoccurance just had this done for peace of mind and lets face it a new set of perkie ones .
5mm is small, so great that it showed up and great that you got it early and hopefully you will not need any further treatment.
Feel free to ask away any questions that you may have.
Tanya