Her2 + not responsive to Tamoxifen?

There are a few threads here about Her2+ BC being resistant to Tamoxifen, or google her2 BC and tamoxifen for info.

I'm 39 and my Onc started me on Arimidex last Nov as I was in Menopause from the chemo and he thinks it's a better option for Her2. He said we would discuss tamoxifen if my period came back or ovary removal to stay on a an AI long term.

My blood tests that I have every 3 months indicate that Menopause looks permanent and I tolerate the Arimidex well with only minor SE's. I'm very fit and active and I think that really helps with any joint pain, I find if I sit for a long time that's when I get a bit of stiffness, but nothing to complain about.

My BMD scan showed ostopenia before commencing the Arimidex so having Zometa to prevent further bone loss.

Lisa, I took the cyp2d6 test to determine if I was metabolizing tamoxifen efficiently because I was not having any side effects whatsoever. The result showed I was an intermediate metabolizer, which means I could be getting a reduced benefit from tamoxifen, and there is some evidence that reduced metabolism for her2+ patients could have significant implications regarding recurrence. My onc switched me to Femara (letrozole), which is an AI shown to be effective for her2, and goserelin (Zoladex) for ovarian suppression. I am having an oopherectomy tomorrow so I won't have to have the goserelin injections and can be sure the AI is doing its job because I will definitely be post-menopausal. The uncertainty about tamoxifen and her2 was causing alot of anxiety for me, and because I am 46 and not planning to have more children I feel this is the right decision for me. All the best to you.

Just my 2 cents, I removed my ovaries too for the same reason. I have been on an AI (femara) for over a year now. I think the side effects are quite managable and they are mild. What I notice the most is a slight joint stiffness, for example in my wrists (as I type), or when I walk down the stairs in the morning. It gets better with exercise. And perhaps I should say that I feel less energetic than I used to. The joint stiffness is worse in the beginning, the first few months. Then it gets better.

I sleep well at night and I have not noticed any weight gain or hair loss. My hair is more dry than it used to be though. Tamoxifen has side effects too. But everyone is different so everyone will have a different experience.

Of course it would be nice not to have to take this stuff, but what can you do....

-Helena.

I also spoke to my onc about this.  Since I am 46, she thinks it's best I go on tamox and see if menses returns since I am in chemopause.  If they do return, she will refer me to an ob/gyn and I will have an ooph.