Before the menopause, the ovaries produce oestrogen. If you haven’t been through menopause (pre-menopausal), your doctor may prescribe one of the following:
- the anti-oestrogen drug tamoxifen
- a drug, such as goserelin (Zoladex®), that stops the ovaries producing oestrogen (ovarian suppression)
- surgery to remove the ovaries (ovarian ablation)
- a combination of tamoxifen with either Zoladex or ovarian ablation (this may be an option for women who don’t want to have chemotherapy).
Some hormonal therapies bring on a temporary or permanent menopause. If you have an early menopause, you will have a scan called a DEXA (dual-energy x-ray absorptiometry) scan to check your bone health.
Women at risk of bone thinning (osteoporosis) may be prescribed drugs called bisphosphonates to protect their bones and are advised to take calcium and vitamin D supplements.
Tamoxifen is the main hormonal therapy for women who have not been through the menopause. It’s taken daily as a tablet. The side effects are similar to the effects of the menopause and may include:
- hot flushes and sweats
- weight gain
Tamoxifen can slightly increase your risk of a blood clot.
You’ll usually have tamoxifen for at least five years. But recent trial results show that taking it for 10 years can reduce the risk of the cancer coming back further. You can talk to your doctor about this. It won’t be suitable for everyone, especially if you have side effects or want to have children. If you’re close to your menopause when you start tamoxifen, your doctor may change your treatment to an aromatase inhibitor after a few years.
Drugs that stop the ovaries producing oestrogen
Zoladex stops the production of oestrogen in the body. It does this by stopping the pituitary gland in the brain from sending messages to the ovaries to produce oestrogen. This stops the ovaries producing oestrogen and causes a temporary menopause. The side effects are similar to menopausal symptoms and include:
- hot flushes and sweats
- joint pain
- low sex drive.
Your nurse will give you Zoladex as a monthly injection under the skin of the tummy (abdomen). When you finish treatment, your ovaries usually start to produce oestrogen again. This means your periods will come back. If you were close to your menopause when you started Zoladex, this may not happen.
Permanently stopping the ovaries working (ovarian ablation)
Other ways of lowering oestrogen levels include stopping the ovaries from working. Doctors sometimes call this ovarian ablation. It can be done with a small operation to remove the ovaries or, rarely, with a short course of radiotherapy to the ovaries. Your doctor may ask you to choose between taking Zoladex or having ovarian ablation.
The operation can be done during a short stay in hospital using keyhole surgery. The surgeon makes a small cut in the tummy area and inserts a thin tube with a tiny light and camera on the end (laparoscope). The surgeon removes the ovaries through the cut using the laparoscope, which has small surgical instruments attached. Women usually recover quickly from this type of operation.
If you have surgery, your periods will stop straight away. After radiotherapy, women usually have one more period before their periods stop completely. It’s important to use contraception for three months after radiotherapy.
Both methods (surgery and radiotherapy) cause a permanent menopause. Becoming infertile because of cancer treatment can be very hard to cope with. There’s more information on the support that’s available in our section on the emotional effects of cancer.
We also have more information about ovarian ablation and coping with menopausal effects.