Ovarian suppression and breast cancer

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

Ovarian suppression is used:

• As part of treatment for breast cancer in women who have not been through the menopause (premenopausal women)
• To protect the ovaries during chemotherapy

Ovarian suppression may also be called ovarian function suppression or OFS.

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

Before the menopause, oestrogen is mainly produced in the ovaries. Removing the ovaries, or stopping them from working, means 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 your body’s fat cells.

Ovarian suppression may be recommended if:

1. You are premenopausal
2. Your breast cancer is ER-positive
3. Chemotherapy is recommended for you

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.

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 to decide whether you would benefit from having ovarian suppression.

The features of the cancer are its:

• Stage
• Size 
• Grade 

Your treatment team may consider other factors, such as whether any cancer cells have spread to your lymph nodes, your age or any pre-existing health conditions.

Ovarian suppression can help 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.

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

Metastatic (secondary) breast cancer and ovarian suppression

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

If you are having ovarian suppression for metastatic breast cancer, you will usually continue having it as long as your treatment team feels you are benefitting from it and any side effects are manageable.

Chemotherapy can cause damage to the ovaries. This can reduce the number and quality of eggs and affect your ability to become pregnant (fertility) when your treatment has finished. Whether your fertility is affected after chemotherapy depends on:

• The type of drugs used
• The dose given
• Your age
• What your fertility was like before breast cancer treatment

Some studies have shown that using hormone therapy drugs to suppress the ovaries may protect them during chemotherapy. This is because hormone therapy drugs, such as goserelin and leuprorelin, temporarily “shut down” the ovaries.

However, we do not know how effective ovarian suppression is as a method of preserving fertility. It cannot replace other fertility preservation methods such as egg and embryo freezing. 

Your treatment team should discuss what treatment they recommend for you and why and any impact it may have on your fertility.

Ovarian suppression can involve:

• Taking hormone therapy drugs, such as goserelin and leuprorelin, to temporarily stop the ovaries from making oestrogen (usually monthly or 3-monthly injections)
• Surgery to remove the ovaries, known as an oophorectomy

Using hormone therapy drugs is the only way of achieving ovarian suppression that may not be permanent. The type of ovarian suppression used is something to consider when making your decision, especially if you want to have children in the future.

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

Hormone therapy

Goserelin (Zoladex)

Goserelin is given as a small implant in an injection. This is the most commonly used drug for ovarian suppression.

Find out more about goserelin.

Leuprorelin (Prostap)

Leuprorelin is given as an injection.

Find out more about leuprorelin.

Triptorelin

Triptorelin can be given for primary breast cancer.

You’ll have the injection either:

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

You’ll have the injection once a month.

Ovarian suppression combined with tamoxifen, aromatase inhibitors or targeted therapies

Ovarian suppression drugs are often combined with other hormone therapies, or targeted therapies. The combination you’ll have will depend on the features and stage of your breast cancer.

Hormone therapy drugs used alongside ovarian suppression

These include:

• Tamoxifen
• Aromatase inhibitors (anastrozole, exemestane, letrozole)

Aromatase inhibitors are not used on their own as hormone therapy in premenopausal women. This is because they are not an effective treatment while the ovaries are still making oestrogen. However, aromatase inhibitors are effective if given alongside the hormone therapy drugs goserelin, leuprorelin or triptorelin.

There is some benefit from having an aromatase inhibitor over tamoxifen, but there are different side effects to consider that can affect your quality of life. Your treatment team will discuss the possible benefits and side effects.

If you continue to have periods after starting an aromatase inhibitor, speak to your treatment team. Your ovaries may not be “switched off” effectively and you may need to have a blood test to check this.

Targeted therapies used alongside hormone therapy drugs and ovarian suppression

These include:

• Abemaciclib (Verzenios)
• Elacestrant (Korserdu)
• Fulvestrant (Faslodex)
• Palbociclib (Ibrance)
• Ribociclib (Kisqali)  

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:

• 1 near the belly button
• 1 near the bikini line
• 1 on the side of the tummy (abdomen)

It’s done under general anaesthetic (where you're given medication so you're asleep (unconscious) and don't feel anything during an operation or procedure). You’ll usually have an oophorectomy 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, and you may have menopausal symptoms.

Ovarian suppression or removing the ovaries can cause side effects. Some people have more side effects than others.

If you’re having ovarian suppression with 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 

If your menopausal symptoms have been caused by hormone therapy or surgery, they’re likely to be more intense than those of a natural menopause.

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

• Weight gain
• Joint pain and stiffness 
• Extreme tiredness (cancer-related fatigue)
• Feeling sick (nausea)
• Difficulty sleeping

Thinning of the bone (osteoporosis)

Lack of oestrogen over a long period of time can cause osteoporosis, a condition where bones lose their strength and are more likely to break.

Your treatment team may suggest a DEXA (dual energy x-ray absorptiometry) scan within the first few months of starting treatment to check your bone density.   

If you’re concerned about your risk of developing osteoporosis, talk to your treatment team.

Find out more about looking after your bones.

Contraception and ovarian suppression

If you’ve had surgery to remove your ovaries

You do not need to use contraception to prevent pregnancy if you’ve had surgery to remove your ovaries.

If you’re having ovarian suppression with hormone therapy

You’re advised not to become pregnant while you’re having ovarian suppression with hormone therapy. This is because the drugs could harm a developing baby.

It’s possible to become pregnant while having hormone therapy, even if your ovaries are "switched off" or 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). Check with your treatment team as not all types are suitable for women with breast cancer.

It can be difficult to cope with the effects of ovarian suppression and an early menopause.

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 metastatic 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.