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 is 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 (these drugs work by blocking the aromatase enzyme which converts androgen hormones into oestrogen and so they reduce the amount of oestrogen in the body). These do not block the effect of oestrogen from your ovaries, and so are only effective in women whose ovaries have stopped making oestrogen – that is after someone has gone through their menopause either naturally or after surgery to remove the ovaries. Other hormonal treatments work by stopping the ovaries from working to produce hormones. This can either be through medical therapy, for example having a medicine called zoladex (goserelin) which switches off the ovary, or through surgical therapy, which would involve removing the ovaries.
Which hormonal therapy is best for each woman depends on several factors, including:
• A woman’s age
• whether a woman has had her menopause (change of life)
• the stage and grade of the cancer
• which other treatments are being used
We are considering women’s experiences of these different hormonal methods.
Zoladex (goserelin) is a type of hormonal therapy. Most breast cancers need supplies of the hormone oestrogen to grow. Production of oestrogen by the ovaries is stimulated by a hormone called luteinising hormone, which is produced by the pituitary gland in the brain. Zoladex stops the production of both luteinising hormone and follicle stimulating hormone from the pituitary gland, which leads to a reduction in oestrogen levels. The cancer cells then grow more slowly or stop growing altogether. The cancer may shrink in size. It can be used on its own or in combination with either tamoxifen or an aromatase inhibitor.
Zoladex is given by injection under the skin of the abdomen (tummy). It is given as a regular injection, either every four weeks or every three months. It can be given by the GP or practice nurse at the surgery. Some women occasionally find the injection slightly uncomfortable, and may notice an area of redness or darker colour at the injection site afterwards.
A few women we spoke with talked about their experiences of Zoladex. One explained why she was given both tamoxifen and Zoladex. Another switched from tamoxifen to Zoladex because of the hot flushes she was having with tamoxifen.
- Age at interview:
- Age at diagnosis:
So I wasn't keen to have surgery immediately but she said' "I think we'll try and shrink it first."
And because it was very, had a very high score for the oestrogen receptors, they put me on tamoxifen. And when I went to see the oncologist the next week, they put me on Zoladex.
So they said' "We'll put you on that, we'll see how that goes, and if that, we'll keep an eye on it and if that shrinks it that's fine. "We'll wait until it gets small enough. "If it doesn't, if it's not seeming to work, then we'll change to chemotherapy."
But even so two years on I still find that I get much more tired. I'm not sure if it's the Zoladex and the tamoxifen which have some of that effect.
- Age at interview:
- Age at diagnosis:
I was on tamoxifen for about four months. They didn't agree with me. So now I have a Zoladex injection every 28 days in my stomach. I get that off the nurse at my doctors'. And as far as that's, three years down the line there's been no return.
Yes.You said you'd had some side effects with the tamoxifen. What kind of side effects were these?
I put on a lot of weight. I was having these, well I still take them, the hot flushes but I call them hot sweats, where the sweat just pours out of you. I still take them a bit, I don't take them as bad.
And I was having stomach cramps. And so they took, took me off them and they gave me this injection, Zoladex.
I think it's just something similar, just a white ball is injected into your stomach. And that takes 28 days to go through your system.
Last reviewed May 2015.
Last updated May 2015.