Anyone had Tamoxifen after Letrozole failed?

Have any other post-menopausal ladies been put on Tamoxifen after Letrozole failed/stopped working - and did it work? I had WLE and clear SNB, rads and then Letrozole but, after just over two apparently clear years, I have swollen axillary nodes on bc side and cancer cells have been found, plus two suspicious areas in my bones.

I have no idea why the Letrozole didn’t mop up any escaped cancer cells, as the bc was strongly ER+. Any ideas?

Bumping this up for you Ann - so sorry you’re experiencing this again, i hope you get some answers.


Thanks, Lynn.

I’m afraid I don’t have an answer Ann but would be interested if anyone else has. I was on a trial which involved 4 months of Letrozole before Mx. It didn’t seem to have made any difference to the tumour or lymph nodes affected. I’m now on chemo then will have rads but most hope seems to be pinned on 5 years of letrozole. I’ve tried asking Onc about this but haven’t had a satisfactory answer. I raised it with a couple of BCNs and they said that some women do better on Tamoxifen, even post-menopausal. Trouble is they have no way of knowing if it is working. Hope your results are better than you’re anticipating - spread to lymph nodes is fairly straightforward.

Hi Ann04

Whilst you wait for someone to reply in a similar situation it might help to talk this through with a trained member of staff on the helpline. Here you share your concerns and discuss any questions you may have with someone who will offer you a listening ear as well as support and information. The number to call is 0808 800 6000 and lines are open Monday to Friday 9 to 5pm and Saturday 9 to 2pm

Best wishes Sam, BCC Facilitator

Ann, please excuse me for saying this, but when you say you have no idea why Letrozole didn’t mop up any escaped cancer cells, it suggests that you might be under the impression that Letrozole is a curative treatment. If that’s the case it’s not quite right. Endocrine therapy doesn’t actually kill cancer cells as such (in the way that chemotherapy is designed to do), rather, it works by starving oestrogen receptive cancer of what it needs to survive (oestrogen). Obviously, by starving cancer, endocrine therapy can sometimes kill it, but the problem is that cancer can and does adapt (as it also does with chemo). When endocrine therapy is prescribed to women with primary BC, it is usually given to prevent re-currence after curative treatments such as surgery, chemo, and/or radiotherapy have been given (although sometimes it is used to shrink a tumour prior to surgery). When endorine therapy is prescribed to women with secondary cancer, it is given as a palliative treatment to try and control progression, rather than cure it.
As we all know, the problem with endocrine therapy and chemotherapy is that cancer can adapt to overcome them. One of the theories as to why endocrine therapy fails is that cancer establishes new pathways to obtain oestrogen. In the case of chemotherapy, one of the theories as to why chemo is not always successful is that it fails to destroy cancer stem cells, and these stem cells re-grow into tumours that are resistant to chemos the cancer has previously been exposed to.
If your cancer has adapted to find a different oestrogen pathway, then this could be the reason your doctors have prescribed Tamoxifen (because Tamoxifen works on cancer receptors to restrict the uptake of oestrogen, whereas Letrozole works by limiting the amount of oestrogen available.
I haven’t tried Tamoxifen myself, but personally, I don’t think you can really assess whether it will work on the basis of others experience, because every cancer is unique. What I will say is that if it was me, and I wanted to to carry on with endocrine therapy I would give it a try. The other option that you could consider is Fulvestrant/Faslodex, which can be given when Letrozole fails. Unfortunately though, NICE recently recommended that it was not cost effective and should not be funded (see link to article below).
However, if your cancer has spread to the bone while you have been taking endocrine therapy, you might want to look at your options a bit more carefully (because you can’t afford experiments).
If you would like some info, I’m happy for you to pm me. I was diagnosed with BC in Nov 2009, and then bone secondaries in February 2010. Although my BC is stongly oestrogen receptive I decided to try the curative route (i.e, chemo, rads, cyberknife sterotactic rads etc), and I’m now NED (no evidence of disease), and am taking Letrozole and bisphosphonates to try and stop recurrence/preserve bone.
Sorry for the length of this post, but hope it helps.

Lemongrove, thank you for your really clear and helpful post. My situation is the other way round to the original poster here - I am pre-menopausal, had 6 months of Tamoxifen post-surgery but then found a new primary and am now on Zoladex to suppress ovarian function plus Letrozole, pending ovaries being removed later this year (I am BRCA1 hence increased ovarian cancer risk hence rather drastic step).

I found it very hard to accept that the drugs hadn’t worked, especially as a) I had had bilateral mx and b) rads and chemo had not been in the picture first time round. Matter of fact posts like yours help with that. And glad to hear that the Letrozole is working for you.



Thanks for your long reply. I do realise that Letrozole does not kill cancer cells and that it reduces oestrogen levels. When I said ‘mop up’, I just meant in a starvation way. I had a WLE/SNB, rads and then Letrozole. I was not given it for secondaries. When I said I didn’t know why it had not worked, it is because the original cells were strongly ER+ and still are and Letrozole definitely caused me to have low oestrogen!

I also know that Tamoxifen works in a different way and as my oncologist has suggested this, with bisphosphonates, I am happy to do this. He said the two areas in my bones are ‘weakly positive’ and could be something else. He didn’t feel the need for chemo just yet.