I've never heard of that hormone. I've been put on Tamoxifen for at least 2 years and then will switch to an aromatase inhibitor. They have less side effects, although I'm doing fine on Tamoxifen.
Some BC's feed on the estrogen in our bodies. The more we have, the more chance of BC. Mine was that type. The good thing is, that type usually responds to chemo better. I've learned that the more fat we have, the more estrogen we have, so that can be a factor in BC. So, I now look at weight loss as a medical necessity more than ever. Also important is a study that showed women who walked at least 3 hours a week have a 50% reduction in BC recurrance. I am proud to say that I've stuck to walking for over a year now. I've kind of slacked off a bit, but at least I'm still doing it. After I recover from this latest surgery, I am determined to get back on track.
I hope that helps.