Goserelin is a hormonal drug used to treat breast cancer in women who have not yet had their menopause.
Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.
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 to grow. This type of breast cancer is called oestrogen-receptor positive (ER positive) breast cancer. Goserelin stops the ovaries making oestrogen.
It is given to reduce the chance of the cancer coming back. You may have it over a few years. Doctors sometimes call this ovarian suppression.
Goserelin can also be used to help to control breast cancer that has spread to other parts of the body (advanced or metastatic cancer).
You usually have goserelin along with other hormonal therapy drugs.
Goserelin is given as a very small pellet injected under the skin (subcutaneously). It is usually injected in the tummy area. The pellet releases the drug slowly as it dissolves under the skin. It is usually given every 4 weeks.
You usually have the first injection at your hospital clinic appointment. After this they can be given by your GP or practice nurse at the surgery. If you are not able to visit the surgery, a district nurse may give you the injection at home.
You may have some pain, swelling, redness or a darker colour around the area that was injected. Let your doctor know if this happens. Painkillers may help.
You may have a local anaesthetic cream to numb the area before the injection.
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.
If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.
Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse 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.
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.
Change in periods
Your periods will usually stop while you are having this treatment. This is caused by the lower levels of oestrogen in the body. When you finish goserelin treatment, your periods are likely to start again. But some women go through their natural menopause during treatment and their periods don’t come back.
Even if your periods stop, you can still become pregnant. You need to make sure that you use effective contraception while having goserelin. You can discuss this with your doctor or nurse.
Vaginal bleeding or dryness
This treatment can cause vaginal changes. Bleeding may happen when you start this treatment or when you change to it from another treatment. If bleeding continues for more than a few days, tell your doctor or nurse.
You can use gels or lubricants to help with vaginal dryness and any discomfort during sex. You can buy these from a chemist, or your doctor can prescribe them.
Hot flushes and sweats
These are common. During a flush, your neck and face may feel warm and look red. Flushes can last for a few seconds or up to 10 minutes. You may have sweats 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.
- Dress in layers of clothes that you can remove as needed.
- Use cotton sheets and have layers of bedding.
- Keep the room temperature 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. Some people continue to have flushes and sweats but they usually stop a few months after treatment finishes.
You can read more about coping with hot flushes in our information about managing menopausal symptoms.
Loss of sex drive
Your sex drive may be lower while taking this treatment. Talk to your doctor or nurse for advice. We have more information about coping with the effects of treatment on your sex life.
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
This treatment can cause swelling and tenderness of your breast tissue. This is called gynaecomastia. Your doctor can give you advice on how this can be prevented or treated.
If you start 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.
High calcium levels in the blood
You may get a mild skin rash. Tell your doctor or nurse if this happens. If you get a severe skin rash it’s very important to contact your doctor straight away. Some women may get acne a few weeks after they start taking goserelin.
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 and keeping to a healthy weight may help with the pain and keeps your joints flexible. Let your doctor or nurse know if it 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
Blood pressure changes
Goserelin may cause low or high blood pressure. Tell your doctor or nurse if you have ever had any problems with your blood pressure. Let them know if you feel dizzy or have any headaches.
Always let your doctor or nurse know about any side effects you have. There are usually ways in which they can be controlled or improved.
Some drugs can affect your fertility (whether you can get pregnant).
Your periods may become irregular or stop. This may be temporary, but for some women it is permanent. Your menopause may start sooner than it would have done.
There may be ways to preserve fertility for women. If you are worried about fertility, it is important to talk with your doctor before you start treatment.
Some medicines can affect the hormonal treatment or be harmful when you are having it. This includes medicines you can buy in a shop or chemist. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.
Medical and dental treatment
If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that 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.