Hi - I also had 5cm+ DCIS hormone negative with grade 3 diagnosis - we had originally discussed lumpectomy when mammogram showed up as 1.5cm - but true extent came to light on MRI. My surgeon put the MRI imaging up on the screen and I could the area light up was about 40% of my left breast so a lumptecomy was just not possible. I could have opted for a partial Mastecomy but I did not want to be left with half a breast - I opted for DXM and am happy with my decision - also has reconstruction and fat grafting - everything has healed really well and zero pain or discomfort. They will never be the same as before with loss of feeling etc but this was best decision for me and my reconstructed breasts do look great. Hope this helps.