Could someone please help me understand Tamoxifen?

Susiemommy, the catch is that your body continues to produce at least some estrogen after menopause. Yes, clots and strokes are potential side effects of Tamoxifen, although not among the more common SEs. However, the much more common side effect of osteoporosis with an AI led me to choose to take Tamoxifen since I already have osteopenia. Unfortunately, there are no choices here without some attendant risks. Hugs and best wishes for you as you are making yet another decision about treatment.

Susiemommy, even if you are postmenopausal, there will still be estrogen floating around your body to fuel cancer cells - IF there are any remaining cancer cells and chemo didn't kill everything already. I say that not to influence you into doing hormone medicine, but just so you are fully informed. Hormone medicine works by further blocking estrogen beyond what menopause would do. In the case of Tamoxifen estrogen is blocked from breast tissue and breast cancer. In the case of AIs estrogen is blocked from a few more body parts too, so those are slightly "stronger" drugs.

I have run the gamut of hormone medicines. They are all quite different from each other in terms of tolerability and side effects. If you work with your MO you will probably be able to find something that is tolerable for you - there are a LOT of hormone drugs out there.

However, every hormone drug has eventually failed for me. All of my recurrences have happened on hormone therapy. An MO would later tell me that my subtype behaves somewhat more like a triple negative cancer, actually. For example, even though I was Stage 1A and node negative, even in the beginning I was only something like 70% ER+ and 80% PR+, with a Grade 3 cancer, and an Oncotype of 32. My subtype of hormone receptor positive breast cancer is was not fully reliant on hormones, and because of that, hormone medicine has not always worked for me. Still, I got a couple of "cancer free" years out of it.

So in your case, your doctors probably have some idea about the nuances of your cancer, and how it will likely behave. Will hormone therapy be effective for you? Will chemo be effective for you? Our individual breast cancers are so different that what works for one person here may not be applicable for you. For those who are 100% ER+, with lower grade cancers, hormone therapy often does work better than chemo. For others, (like me) not so much. It really depends.

I don't know where you fall on this spectrum of course, but one of the hard truths to this disease is that things do not get easier if you have a metastatic recurrence. Sometimes people say "if it's going to happen, it's going to happen..." but I think it's good to delay that happening if possible. Hormone medicine can do that.

Best wishes whatever you decide, truly.