Progesterone too?

So I have always wondered, what about progesterone in breast cancer treatment. A big part of your breast cancer diagnosis is its hormone status. My breast cancer was the most common type - ER+/PR+/Her2-. That translates to estrogen and progesterone positive and her2 negative.

This determines a big part of your treatment. If you are estrogen positive you are treated with Tamoxifen and/or one of the aromatase inhibitors. If you are Her2 positive, you can receive Herceptin. But no one ever said anything about progesterone. I always wondered why it was part of the diagnosis if it didn't affect treatment. I mean why bother?

But now things have changed. New research has found a way to control progesterone as well:

"Cancers with progesterone receptors are known for growing more slowly, however scientists have not been able to exploit this fact until they discovered the way they interact with estrogen, which causes the growth of some tumors"

"In the new study, researchers found that progesterone receptors interact with estrogen receptors in the tumor, changing their behavior and slowing the tumor's growth."

"Roughly 75 percent of women with breast cancer have tumors with the estrogen receptor, and 75 percent of those tumors also have progesterone receptors -- suggesting more than half of these patients could benefit if the treatment is shown to be successful."

And the outcome should be a cheap and safe treatment option.I'm all for this.