Tamoxifen impact on menopause

[emma-lou]

Hi there,

My question is about the impact of tamoxifen and the menopause.

I had Breast Cancer 7 years ago, which was treated by having mastectomy and hormone therapy. I was 48 and so I suppose I verging on perimenopausal then, although I was still having normal periods.

The effects of tamoxifen were fairly brutal; my periods stopped within the first year and I had a range of very difficult menopausal symptoms, most of which I am still dealing with today. I stopped taking tamoxifen 2 years ago, but one year ago I had a post- menopausal bleed, which put me on the gynae cancer two week pathway, but scans hysteroscopy and a biopsy found no evidence of cancer, thankfully.

I had another bleed this summer and went through more invasive tests because of evidence of thickening in the womb. Again, thankfully the results showed nothing sinister and I was discharged.

Everything was fine until last month when I had more bleeding but this time it was a full on period with other more familiar symptoms leading up to it (e.g., sore nipple, spots, feeling more emotional etc). Then lo and behold, the same thing has happened again a month later (now!)

So, I can only conclude that I’m not actually post menopausal after all and that after 5 years of being under hormone suppression, my reproductive system has woken up and decided it’s not quite finished yet!

I know periods can return at the end of hormone treatment, but what seems rather strange is:

1. It’s taken 2 years for this to happen.

2. I’m now 56, so thought I would naturally be post menopausal by now (even if I hadn’t had any hormone treatment.)

I’m wondering if this is unusual, or more common than I might think? Has anyone had a similar experience?

My family are worried and think I should go to my GP, but I don’t want to waste their time because:

a) although it’s annoying, I don’t think anything is ‘wrong’ because I’ve been checked out recently. Is that a fair assumption?

b) to be honest, I’m not convinced my GP I’ll be able to shed much light on the situation – I think this is a most specialised query which Breast Care Nurses more likely to be knowledgeable about.

So having given all that context and background information, my questions are:

1. Is this resumption of my periods ‘par for the course’ given my circumstances and age?

2. Could this be because while hormonally suppressed on tamoxifen, my reproductive system was effectively ‘frozen’, with the body clock paused, but has now restarted, if that makes sense? Not sure if it works like that?

3. Does this mean that I should expect to go through another menopause, maybe in a couple of years time when my ovaries have run out of steam?

Any advice would be much appreciated, thank you!

[trix1]

Hi

I saw your post, and could not pass by, it is a very interesting question thank you for writing it and asking them so well. I hope you get the advice you need soon. Well wishes to you. Thank you

[emma-lou]

Thanks Trix1.

[roses4]

Hi Emma-Lou, I am 49 and just started taking Tamoxifen and I am very interested in what you find out. I really hope you do manage to get some answers as I think alot of women will be in the same situation. Thank you for sharing.

[emma-lou]

Thanks Roses4, I appreciate your comment. Unfortunately, no one has replied yet, so I’m no nearer to getting any guidance on this. I’m hoping a nurse will see it and have some helpful information.

[Jill1998]

Hi @emma-lou , it might help to talk this through with the Breast Cancer Now nurses on the helpline ?

0808 800 6000

[poorlyboob]

Hi emma-lou

I dont think this will help much. I am 55 and was still having regular periods prior to starting tamoxifen in April 2023. Over the past year, I seem to have a period about every 3-4 months with my last in August. I was under the impression that tamoxifen would have stopped them completely. I dont know if it is tamoxifen or menopause that is making them so infrequent.

Probably not what you are looking for, but just my experience at the moment.

Best wishes x

[orchid2]

I’ve not started hormone treatment yet (still on chemo) but the impression I got from my oncologist was that if tamoxifen doesn’t stop my periods she’ll put me on AIs, I think she basically doesn’t want me to have periods again as that means I have too much oestrogen in my body. I was ER8 though, maybe someone with a lower er score can risk having periods returning?

I think what I’m trying to say is, your oncologist might want to know at that can review whether it’s ok to have periods returning?

[sal1]

Hi

Just extending on what @orchid2 mentioned. My oncologist started me on Tamoxifen and said something along the lines of “many stop their periods, but not all”. I think because I have PCOS and I was ER8, they changed me to Zoladex, which definitely stops periods while receiving it and moved to an AI.

My take and understanding is that Tamoxifen only simulates menopause, because it’s the tablet which is stopping the estrogen. I guess it’s logical that when you stop taking the tablets, and the effects wear off, the creation of estrogen is determined by your natural state. It could take sometime for hormones to settle after being artificially stopped.

I’m no doctor … but it sounds to me, that now you have stopped Tamoxifen and you are still producing Estrogen. Perhaps not the levels from your younger years, but in line with perimenopause?

You could ask your GP to refer you to Gynae, or request some hormone blood tests to confirm your levels. And as said above, speak to your oncologist, they may want to extend the hormone therapy until you are in “established menopause” (I think that’s the term they used to me!). They can also rule any other issues that could or could not be related to Tamoxifen. Certainly worth perusing with the professionals.

Best wishes