TAMOXIFEN - What does it really do? How is it really different?

Today I got an e-mail from   a CA Breast Cancer site I once supported.  One issue mentioned in the  "letter" from their Exec Director, was a study on aromatase inhibitors.  I don't take them, but I still glanced at her June 7 post.

She mentions the "San Antonio Breast Cancer Symposium which showed that extending treatment with tamoxifen reduced both recurrence of and death from breast cancer."  and mentions that she wrote about that symposium and the Atlas Study at that time.

I clicked the link to what she had written then.  And was dismayed to find this: "Tamoxifen is an anti-estrogen drug given to women with hormone sensitive breast cancer to prevent spread and recurrence."

 In fact, anti-estrogen is the opposite of  Tamoxifen--   

Pre-menopausal women get Tamoxifen because it does NOT destroy or prevent estrogen.

Here's what Tamoxifen does: 

Cancer Research UK:
" Tamoxifen works by locking on to the oestrogen receptors to block oestrogen from attaching to them. The oestrogen cannot then stimulate the cells to divide and grow. "  (bold is mine)  

 For me, this is a very important difference, a vital difference.  At my age, if my body produces a bit of estrogen, I want to consider that that might not be all bad!  

So I refer you to what the Nat'l Cancer Institute says on hormone treatment and what SERMS like Tamoxifen can do. 

 "Most SERMs behave as estrogen antagonists in some tissues and as estrogen agonists in other tissues. For example, tamoxifen blocks the effects of estrogen in breast tissue but acts like estrogen in the uterus and bone."

https://www.cancer.gov/types/breast/breast-hormone-therapy-fact-sheet  

PS Even my oncologist mentions now and then that Tamoxifen is thought to have deposited some new bone on hips. And one of my hips is where I'm hoping for a little help with my osteoporosis.