Ovarian suppression and breast cancer

Ovarian suppression describes treatments that stop the ovaries from making oestrogen, either permanently or temporarily.

You might hear different terms for ovarian suppression such as ovarian function suppression and ovarian ablation.

Ovarian suppression is used:

• As part of treatment for breast cancer in premenopausal women (women who have not yet reached the menopause)
• To try to preserve fertility during chemotherapy

Some breast cancers use oestrogen in the body to help them grow. These are known as oestrogen-receptor positive or ER+ breast cancers. 

Before the menopause, oestrogen is mainly produced by the ovaries. 

If the ovaries are removed, or if they are stopped from working, there’s less oestrogen in the body to help the cancer to grow. This is ovarian suppression.

Small amounts of oestrogen will still be produced by fat cells.

Ovarian suppression may be recommended if all the following apply:

• You are premenopausal
• You've had chemotherapy
• Your breast cancer is ER+

The benefit may be more in younger women (under 35) compared with women older than this. 

Evidence suggests that women who are premenopausal after chemotherapy may benefit most from ovarian suppression. Older premenopausal women may not get as much benefit from ovarian suppression after chemotherapy.

Ovarian suppression might be offered to people with primary breast cancer or secondary breast cancer. 

Primary breast cancer and ovarian suppression

Ovarian suppression can be used as part of your treatment for primary breast cancer. Your treatment team will look at various features of the cancer such as the stage, size and grade to decide whether you would benefit from having ovarian suppression as part of your treatment. Other factors may also be considered.

Ovarian suppression can help to reduce the risk of the breast cancer coming back (recurrence) or a new breast cancer developing (a second primary breast cancer).

It may also be a treatment option for some women who choose not to have chemotherapy.

Secondary breast cancer and ovarian suppression

Ovarian suppression can be used to treat premenopausal women with secondary breast cancer. Your treatment team will discuss with you if this is an appropriate treatment for you.

Chemotherapy can affect the ovaries, reducing the number and quality of eggs and make it more difficult to get pregnant.

Some studies have shown that ovarian suppression using hormone therapy drugs may protect the ovaries during chemotherapy as it temporarily ‘shuts down’ the ovaries. However, the effectiveness of ovarian suppression for preserving fertility is still debated and cannot replace other fertility preservation methods like egg and embryo freezing.

More research is needed looking at the role of ovarian suppression during chemotherapy to preserve fertility.

Your treatment team should discuss what treatment they recommend for you and why.

Ovarian suppression can be achieved by:

• Hormone therapy – usually monthly or three-monthly injections
• Surgery to remove the ovaries (oopherectomy)

Your treatment team should help you decide which treatment is best for you. 

Using hormone therapy is the only way of achieving ovarian suppression that may not be permanent. This could be something to consider when making your decision, especially if you hope to have your own children in the future.

Hormone therapy

Some drugs stop the ovaries from making oestrogen. 

Goserelin

Goserelin (Zoladex) is the most commonly used drug used in ovarian suppression. It comes as a very small pellet (implant) in a pre-filled syringe. It’s given as an injection into your abdomen once a month. 

Leuprorelin (Prostap)

Leuprorelin (Prostap) is given as an injection once a month, or sometimes every 3 months. It can be given either:

• Into muscle in your leg or buttocks
• Under your skin (subcutaneously) into fatty tissue in your upper arm, thigh or abdomen

Triptorelin

Triptorelin is given as an injection once a month either: 

• Into your muscle, usually in your buttock
• Under your skin into your abdomen

Ovarian suppression combined with tamoxifen, aromatase inhibitors or targeted therapies

If you are having one of the above injections for ovarian suppression this is often combined with another hormone therapy such as tamoxifen or drugs known as aromatase inhibitors.

Research has suggested this may reduce the risk of the breast cancer coming back for some premenopausal women who have had chemotherapy.

There may be a small extra benefit from having an aromatase inhibitor over tamoxifen, but there might be different side effects to consider that can affect your quality of life. Your treatment team will help you discuss the possible benefits and side effects.

Aromatase inhibitors are not used on their own as hormone therapy in premenopausal women because they are not an effective treatment while the ovaries are still making oestrogen, but they can be given alongside ovarian suppression with goserelin, leuprorelin or triptorelin. If you continue to have periods after starting an aromatase inhibitor, speak to your treatment team as your ovaries may not be ‘switched off’ effectively. Sometimes blood tests are done to check this.

Ovarian suppression can also be used combined with aromatase inhibitors and some targeted therapies like abemaciclib, palbociclib, and ribociclib. 

Your treatment team will discuss with you what they recommend and why. 

Surgery to remove the ovaries (oophorectomy)

An operation to remove the ovaries is called an oophorectomy. The fallopian tubes, which are very close to the ovaries, are usually removed at the same time.

The operation is usually done as ‘keyhole’ surgery using a flexible thin tube with a camera lens attached (a laparoscope). Three small cuts are made, one near the belly button, one near the bikini line and one on the side of the abdomen. It’s done under general anaesthetic, usually as a day case but some people stay in hospital overnight.

Sometimes it isn’t possible to remove the ovaries with keyhole surgery. In this case they will be removed through a small cut made below the bikini line.

Removing the ovaries will mean an immediate and permanent menopause. Your periods will stop straight away.

Everyone reacts differently to drugs and treatments and some women have more side effects than others. 

If ovarian suppression is given in addition to chemotherapy or other hormone therapies, it’s sometimes difficult to know which side effects are being caused by which treatment. 

It’s important to talk with your treatment team about any side effects you’re having and how best to manage them, whether or not they are listed here.

Menopausal symptoms

Menopausal symptoms are common, including:

• Hot flushes
• Night sweats
• Vaginal dryness
• Mood changes
• A decrease in sex drive 

Ovarian suppression achieved by hormone therapy or surgery is more likely to cause menopausal symptoms than a natural menopause. 

Menopausal symptoms, especially if sudden or intense, can affect your confidence and may have an impact on both you and your partner. 

As well as the symptoms mentioned above, you may experience:

• Weight gain
• Joint pain and stiffness 
• Fatigue (extreme tiredness)
• Feeling sick (nausea)

Although these symptoms may be quite intense in the beginning, they usually improve over time. 

Osteoporosis

Lack of oestrogen over a long period of time can cause thinning of the bones (osteoporosis). 

Younger women having ovarian suppression will usually be offered a DEXA scan within the first few months of starting treatment. A DEXA scan measures bone density. 

If you are having ovarian suppression to try to preserve fertility during chemotherapy, an injection is usually given at least 2 weeks before chemotherapy starts, then every 4 weeks during chemotherapy.

Ovarian suppression as a treatment for primary breast cancer is usually given for between 2 and 5 years.

If you are having ovarian suppression for secondary breast cancer, you will usually continue for as long as the treatment is effective.

If you have had surgery to remove your ovaries, you don’t need to use contraception.

You’re advised not to become pregnant while you’re having ovarian suppression with hormone therapy because the drugs could harm a developing baby. It’s possible to become pregnant while having hormone therapy, even if your periods have stopped or become irregular.

Use a non-hormonal method of contraception to avoid getting pregnant, such as condoms, Femidoms or a diaphragm.

It may also be possible to use a coil (IUD or intrauterine device). However, you would need to discuss this with your treatment team as not all types are suitable for women with breast cancer.

For some women coping with the effects of ovarian suppression and possibly an early menopause brought on by treatment can be difficult.
Your treatment team will discuss with you the possible benefits and risks of ovarian suppression. 

If you have ongoing side effects, tell your treatment team so they can suggest how best to manage them. 

Research has shown that younger women are more likely to stop taking hormone therapy early if they don’t get help with possible side effects so it’s important to get support if you need it. Not having hormone therapy for the recommended time may increase the risk of breast cancer coming back.

Going through the menopause prematurely can create feelings of loss, and make you feel isolated from women your own age. 

You don’t have to cope on your own. Some women find it helpful to discuss their feelings and concerns with their breast care nurse or GP. If you feel you’d like to talk things through in more depth, a counsellor or psychologist may be more appropriate.

You can also call our free helpline and talk with our nurses or use our Ask Our Nurses email service - see below.

Sharing your feelings with someone who's had a similar experience can be helpful. We run services especially for younger women with primary breast cancer:

• Younger Women Together support events for women under 45 - see below.
• Someone Like Me – be put in touch with someone with a similar experience of breast cancer, so you can talk through your worries and share experiences over the phone or by email. Please see below.

If you're a younger woman with secondary breast cancer, you can find out more about our Living with secondary breast cancer events, or our Younger Women with Secondaries Together events, just below.