They tried tamoxifen to shrink mine for 5 mths. It did not work. I had double mastectomy and full reconstruction then chemo and radiation. After that back on tamoxifen for a few years, now just switched to an aromatase inhibitor, see how that goes. You're initial pathology staging is not the true one, that comes when they remove it and test it. So don't panic at the size they say. Biology plays a part too.