Goserelin for breast cancer (Zoladex®, Zoladex LA®)

This information is about a hormonal therapy drug called goserelin when it is used to treat breast cancer.

What is goserelin (Zoladex®, Zoladex LA®)?

Goserelin is a hormonal therapy drug used to treat breast cancer. It may also be called Zoladex® or Zoladex LA®.

It is usually given with other hormonal therapy drugs.

It is best to read this information with our general information about hormonal therapies and breast cancer.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

This information is for anyone of any gender having goserelin as part of treatment for breast cancer. Goserelin can also be used to treat prostate cancer. We have separate information about goserelin for prostate cancer.

How goserelin works

Hormones are chemicals that our bodies make. Hormones act as messengers and help control how cells and organs work. Hormonal therapies are drugs that change the way hormones are made or how they work in the body.

Many breast cancers rely on the hormone oestrogen (or estrogen) to grow. This type of breast cancer is called oestrogen-receptor positive (ER positive) breast cancer. Goserelin stops the body making oestrogen. This lowers oestrogen levels, which may stop breast cancer growing, or shrink the cancer.

Having goserelin

Goserelin is given as a very small pellet injected under the skin (subcutaneously). It is usually injected in the tummy area (abdomen). The pellet releases the drug slowly as it dissolves under the skin. 

Zoladex® is given every 4 weeks. Zoladex LA® is given every 12 weeks.

You usually have the first injection at your hospital clinic appointment. After this your practice nurse or GP can give it to you at the surgery. If you are not able to visit the surgery, a district nurse may give you the injection at home. 

Tell your doctor or nurse if you are taking any medicines to thin your blood, as this may increase bruising.

Your nurse or doctor will talk to you about your treatment plan.

Injection site

The area near the injection may become:

  • painful
  • swollen
  • red or darker. 

If this happens, let your doctor know. Painkillers may help.

You may have a local anaesthetic cream to numb the area before the injection.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. You may have some rarer side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor, nurse or pharmacist can give you drugs to help control some side effects. It is important to take them exactly as they tell you. This means the drugs will be more likely to work for you. Your doctor, nurse or pharmacist will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Common side effects

Hot flushes and sweats

Hot flushes are a common side effect of this treatment. During a flush, your neck and face may feel warm and look red. Flushes may last from a few seconds up to 10 minutes. You may have sweats and then feel cold and clammy. Some people feel anxious or irritable during a hot flush.

There are things you can do to try to reduce flushes:

  • Wear clothes made from natural fabrics, such as cotton.
  • Wear layers of clothes that you can remove if you feel hot.
  • Use cotton bed sheets and have layers of bedding that you can remove if you feel hot.
  • Keep room temperatures cool or use a fan.
  • Have cold drinks rather than hot ones. Try to avoid drinks with caffeine in them.

You may have fewer hot flushes and sweats as your body adjusts to hormonal treatment. Or your doctor can prescribe drugs to help. Flushes and sweats usually stop a few months after treatment finishes, but some people continue to have them.

You can read more about coping with hot flushes.

Vaginal bleeding and effects on periods

This treatment can cause irregular vaginal bleeding for up to a month after the first injection. After this, periods will usually stop. If you have vaginal bleeding, tell your doctor or nurse.

Even with no periods, you can still become pregnant if you have not yet been through menopause. You need to use non-hormonal contraception to prevent a pregnancy while having goserelin. Your doctor or nurse can tell you more about this.

Monthly periods may start again when you stop goserelin treatment. But if you had a natural menopause during treatment, your periods may not come back.

Vaginal dryness

This treatment can cause vaginal dryness and a lower sex drive. Non-hormonal creams, gels or lubricants may help with vaginal dryness and discomfort. You can buy these from a chemist, or your doctor can prescribe them. We have more information about cancer and sex.

Erection problems

It is common to lose your sex drive during treatment with hormonal therapy. This can cause erection problems. Things may return to normal after you stop taking the drug. But some people continue to have problems after treatment is over. Your doctor can prescribe treatments to help with erection problems. But these treatments will not increase your sex drive.

Mood changes

You may have some mood changes during this treatment. You may feel low or depressed. Let your doctor or nurse know if you notice any changes.

Breast swelling or tenderness

You may get swelling and tenderness of your breast tissue. Talk to your doctor or nurse if this is a problem.

Tumour flare

If you have this treatment for cancer that has spread to the bones, you may get pain in the bones when you start taking it. Doctors call this tumour flare. Your doctor can give you treatment to help with this.

Skin changes

This treatment may affect your skin. It may cause a rash, which might be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.

Always tell your doctor or nurse about any changes to your skin. They can give you advice and may prescribe creams or medicines to help. Skin changes usually improve when treatment finishes.

Hair thinning

Your hair may become thinner when you are taking this treatment. This is usually mild. Ask your nurse for advice if you are worried about this.

Headaches

This treatment may cause headaches. If you have headaches, tell your doctor. They may give you painkillers to help.

Muscle or joint pain

You may get pain in your muscles or joints. If this happens, tell your doctor so they can give you painkillers. Being physically active may help with the pain and keep your joints flexible. Keeping to a healthy weight may help too. Tell your doctor or nurse if the pain does not get better.

Bone thinning (osteoporosis)

If you take this treatment for several months or more, you may get bone thinning. This is called osteoporosis. This can increase your risk of a broken bone (fracture). You may have bone density scans to check your bone health before and during treatment.

Doing regular exercise, such as walking, can improve your bone health. Eating a healthy diet can help too. Your doctor may prescribe drugs called bisphosphonates to help protect your bones. They may also advise you to take calcium and vitamin D supplements.

Tingling in your fingers or toes

Goserelin may cause changes in sensation in the hands and feet. This is usually mild. Let your doctor or nurse know if you have this.

Blood pressure changes

Goserelin may cause low or high blood pressure. If you have ever had any problems with your blood pressure, tell your doctor or nurse. Let them know if you feel dizzy or have any headaches.

Weight gain

You may gain weight when you are having this treatment. Eating healthily and being active can help you keep to a healthy weight. Your doctor, nurse or a dietitian can give you more advice.

Less common side effects

High calcium levels in the blood

If you have goserelin to treat breast cancer that has spread to the bones, it may cause high calcium levels in the blood (hypercalcaemia). This is not common. Signs of this include:

If you have any of these symptoms, let your doctor know straight away so they can treat it.

Raised blood sugar levels

This treatment can raise your blood sugar levels. If you have a raised blood sugar level, you may:

  • feeling thirsty
  • needing to pass urine (pee) more often
  • feeling tired.

Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this. You may need to change your insulin or tablet dose.

Effects on the heart

This treatment can affect the way your heart works. Your doctor may do tests to see how well your heart is working. You may have these tests before, during, and sometimes after treatment.

Contact a doctor straight away if you:

  • have pain or tightness in your chest
  • feel breathless or dizzy
  • feel your heart is beating too fast or too slowly.

Other conditions can cause these symptoms. But it is important to get them checked by a doctor.

Other information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • throbbing pain or swelling in a leg or arm
  • reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
  • suddenly feeling breathless or coughing.

Always call 999 if you have:

  • chest pain
  • difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Contraception

If you are a woman or person assigned female at birth, your doctor will advise you not to become pregnant while having this treatment. The drug may harm a developing baby.

It is important to use an effective, non-hormonal contraception during your treatment and for a few months after it finishes. Even if your periods have stopped or are irregular, you still need to use contraception. If you are not sure or have questions about contraception, talk to your doctor or nurse.

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment finishes. This is because the drugs could be passed to the baby through breast milk.

Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 March 2022
|
Next review: 01 September 2024
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

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