Breast Cancer in women

Hormonal (Endocrine) Therapy: Tamoxifen

Hormonal or endocrine therapies are treatments which either reduce the levels of hormones in the body or block their effects on cancer cells. They are often given after surgery, radiotherapy and chemotherapy for breast cancer to reduce the chance of the cancer coming back, but may also be given before sugery.
 
Hormonal therapies are only effective in women whose cancer cells have receptors for oestrogen and/or progesterone on their surface. This is known as being oestrogen-receptor positive (ER+) or progesterone-receptor positive (PR+). It means that the breast cancer cells are affected by oestrogen or progesterone. These are female hormones that the body produces naturally and that can stimulate breast cancer cells to grow. When a cancer is removed and the tissue is studied in the laboratory, testing for whether these hormonal receptors are present is one of the checks that are normally done.
 
There are many different types of hormonal therapy, and they work in slightly different ways. Hormonal therapies for breast cancer include the drug tamoxifen which is from a group of medicines known as a SERM (selective oestrogen receptor modulator). These block the effect of oestrogen on tissue receptors.

Another family of drugs which act to reduce hormone levels are the medicines known as aromatase inhibitors, which work by blocking the aromatase enzyme and reducing the amount of oestrogen in the body. They are only effective in women whose ovaries have stopped making oestrogen – someone who has gone through menopause either naturally or after surgery to remove the ovaries.

Other hormonal treatments work by stopping the ovaries from producing hormones by using medicines such as Zoladex (goserelin) which switch off the ovary, or through surgical therapy (removal of the ovaries).
 
Which hormonal therapy is best for each person depends on several factors, including:

  • age
  • menopause
  • the stage and grade of the cancer
  • other treatments being used

Tamoxifen

Here women spoke about their experiences of tamoxifen, a hormonal therapy known as an anti-oestrogen drug.

Tamoxifen works by stopping oestrogen in the body from attaching to breast cancer cells and preventing their growth, lowering the risk of breast cancer coming back (recurring) after treatment. It is the main hormonal therapy drug given to women who haven’t been through menopause (premenopausal). It is also sometimes given to women after (post) menopause, and it can also be used for men with breast cancer.

Tamoxifen comes as tablets and is usually given on a treatment course for 5 to 10 years). Though taking tamoxifen for longer does come with an increased risk of developing womb (endometrial) cancer, the benefits typically outweigh this risk (Cancer Research UK 2022). This is a decision the individual would normally make in consultation with their breast cancer specialist. 

Experiences with Tamoxifen treatment

Many women explained why they were prescribed tamoxifen and discussed the benefits of taking it. A few women had to stop taking HRT (hormone replacement therapy) drugs containing oestrogen and progestin when diagnosed with breast cancer and were given tamoxifen. One woman explained why she was initially against taking these tablets.

Explains why she was given tamoxifen.

Explains why she was given tamoxifen.

Age at interview: 59
Sex: Female
Age at diagnosis: 56
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And again, having seen the person about radiotherapy, I was so relieved because she said that I didn't need chemotherapy because when I was first diagnosed with the invasive cancer I was put on tamoxifen straight away.

She said "tamoxifen plus radiotherapy, that's all you need."

And one of the things of course the, it turned out to be an oestrogen receptive positive tumour, so tamoxifen would sort that out. Well that's the general practice for that.

So I thought' "Oh, that's great."
 

Comments on giving up HRT and taking tamoxifen.

Comments on giving up HRT and taking tamoxifen.

Age at interview: 56
Sex: Female
Age at diagnosis: 53
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So after that I went onto tamoxifen.

I think it was a few weeks after the end of the radiotherapy, and they had explained that when I was in the hospital that almost certainly they would give me tamoxifen, and it's usually anticipated that you'll have it for a period of about 5 years.

The main side effects of tamoxifen are apparently menopausal symptoms.

I've been on HRT because I had very bad hot flushes, so when I was diagnosed with breast cancer I had to come straight off the HRT, then I took the tamoxifen and so I had a recurrence of all of the hot flushes, that was the worst thing that I had to deal with, I didn't really have anything else that worried me but I used to wear, I was wearing summer clothes really all the year round.

Although a few women had no side effects with tamoxifen, most experienced some symptoms. Hot flushes or sweats were common and sometimes they interrupted sleep. A few women suggested taking evening primrose oil, but there is no scientific evidence of its value for this.

Comments on her concerns about tamoxifen.

Comments on her concerns about tamoxifen.

Age at interview: 43
Sex: Female
Age at diagnosis: 43
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And I didn''t want to take it. I didn''t want to take it at all because I didn''t want to go into the change of life or have all these side effects, or to have to take a pill every day of life my life. It''s not something that I really wanted really.

And then of course I have got side effects with hot flushes and all the rest of it.
 

Discusses how she has learnt to cope with the hot sweats she experienced with tamoxifen.

Discusses how she has learnt to cope with the hot sweats she experienced with tamoxifen.

Age at interview: 47
Sex: Female
Age at diagnosis: 43
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When I came out of hospital, well no when I was in hospital, I was put on tamoxifen straight away. And all the menopausal symptoms came in.

Hot sweats are horrendous. And the hot sweats are worse when I've had the chemotherapy.

So, for about two weeks from when I first have it until then, I'm up probably four, five times in the night. I wake up, go to the loo and just lie there and all the sweat starts popping, you know. But I've got used to it, and now I sort of, don't laugh, but it's not a grimace any more, it's like' "Oh here we go again", you know.

And again it's just something that it's going to happen. And so, you know, I just think' "Well I've got to live with this." And so when, when I do get woken up and I'm sweating I try and keep my eyes closedand just lie there and relax and not get tense because then as soon as it cools, I cool down again, I go back to sleep.

So it's not too bad.
 

Some women said they gained weight while they were taking tamoxifen. Other women complained of tiredness, and a few had irregular periods. Uterine complications affected a few women. Women who have taken tamoxifen over a long period of time have an increased risk of womb cancer (endometrial cancer). Abnormal vaginal bleeding can be an early sign, so it is very important to get any unusual, changing or post-menopausal bleeding checked straight away by your GP. When womb cancer is found early, treatment is very successful. Mood swings, panic attacks, nausea, insomnia, indigestion, and aches in the bones were some of the side effects experienced by people we talked to. Verite said she had a rare side effect, temporary blindness in one eye, and problems with her skin.

Comments that she gained weight as a result of taking tamoxifen.

Comments that she gained weight as a result of taking tamoxifen.

Age at interview: 57
Sex: Female
Age at diagnosis: 54
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So you were taking that throughout all the chemotherapy and radiotherapy as well?

I took it, I've taken it all the way through and I'm still taking and it's now, gosh it's nearly, it's 2 years since I finished my treatment now. And I'm still taking it and I've only missed it one night, which I think is quite good (laughs). So yes I take that.

How do you feel about taking that every day for a long, indefinite time period, perhaps?

I don't mind at all. I've read up, read quite a bit about. I think it's, I think it is invaluable. I think it's one of the drugs that is proved to be doing some good, so I'm happy. I mean it does make me a little bit into blob woman. It does put on some weight but, you know, again it's a small price to pay, to be, to be alive and to do all the things I want to do now.
 

Verite's sight problem was treated successfully by an ophthalmologist and she used various creams she bought in France to treat her skin.

Verite's sight problem was treated successfully by an ophthalmologist and she used various creams she bought in France to treat her skin.

Age at interview: 61
Sex: Female
Age at diagnosis: 54
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I was handed tamoxifen, and I woke up a week later to find I was blind in one eye. And I went up to see the oncologist and he said, “Oh, um, um, I’ve never seen this before.” Luckily the Chaplain was passing by outside. So I collared him and I said, “[Chaplain’s name], what do I do?”  “Oh” he said, “That’s a side effect of tamoxifen. It’s recognised. I’ll look it up in my papers.” And sure enough it said X percent of us get this in our eye. So I went off to see a French ophthalmologist who sorted me out beautifully.

And then about two or three days after I’d finished off with the ophthalmologist, I wake up and I’ve got bloody sheets. And I’ve got horrible skin lesions all over my body and my peeling skin and everything. So again I rush up to the hospital. And the nurse peels off more skin. And says, “Oh I don’t know what to do about this.” So I made an appointment myself to see the dermatologist who dared to tell me, “It’s your age.” Well I knew full well that that was, it couldn’t possibly happen overnight if it were age. So I took him up on this and he just swept out saying, “I haven’t got time to answer questions.”

So this time I thought, “No, I really, this is serious.” So I went on the internet and found that the French are the best at treating this. So I went off to Roche Posay where they treat about eight thousand skin problems a year. So I reckoned they knew what they were doing. And sure enough they did. They gave me lots of nice products. I was examined very, very thoroughly. Swabs taken and all sorts of things like that. And came back with a huge box of  lovely products and, since then, every time I can feel a skin lesion about to burst out, I slap more of the products on.

Tamoxifen can also interact with other medications such as warfarin and types of antidepressants.
 
Some women said they felt wary of completing their hormone therapy or were reluctant to stop taking it. One woman said she had withdrawal symptoms. A few wanted to take tamoxifen in order to feel they were doing all they could. Others, however, were pleased not to be taking any more medication.

Considers her withdrawal symptoms after completing hormone therapy.

Considers her withdrawal symptoms after completing hormone therapy.

Age at interview: 82
Sex: Female
Age at diagnosis: 60
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So consequently I've been on these tamoxifen until January and that.

But since then the, my GP doesn't think so because I went back to him, but I personally think so, being on them for so long and stopping them like that I've had withdrawal symptoms a bit.

So I'll get, I've been getting hot flushes a bit. Not too bad but I'll have them again and that sort of thing.
 

Would prefer to be on tamoxifen even though tests suggest it would probably make little difference in her case.

Would prefer to be on tamoxifen even though tests suggest it would probably make little difference in her case.

Age at interview: 51
Sex: Female
Age at diagnosis: 48
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You said you wanted to go on tamoxifen because you haven't been prescribed it? Why do you feel so strongly about that?

Because I'll grab anything that's going [laughs]. I think if it's borderline then I should have been put on it. I'm going to find out why, properly, next week, why I wasn't put on it and see if they'll put me on it. I think if there's any doubt about it they should've done it in the first place. And I also think it's like a prop, you know, it's something that you probably think is helping you. So it's psychological as well.

Because there's no other treatment now for you to have?

Yes.

You've finished that episode?

Yes. In fact I know somebody who's been on it for ten years and she nearly cracked up when she was taken off it because she said it's like an insurity. So, yeah I suppose because it's the only other treatment available, then yes.
 

A few discussed the reasons they were not given tamoxifen or why they declined it. Doctors prescribe drugs if they believe that the additional chance of cure outweighs the side effects. The patient has a chance of weighing pros and cons and many thought that the benefits of treatment outweighed the temporary side effects. 

Discusses why she declined having tamoxifen.

Discusses why she declined having tamoxifen.

Age at interview: 49
Sex: Female
Age at diagnosis: 30
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I've not had tamoxifen because when I was first treated tamoxifen was quite new.

And I've survived all this time without tamoxifen so when it was offered to me last year, and my initial tumour was not tested for whether it was oestrogen receptive or not, I declined to have tamoxifen because I've survived anyway.
 

See also 'Tamoxifen for men with breast cancer'.

Last reviewed November 2024.
Last updated November 2024.

 

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