Goserelin is a hormone therapy drug used to treat breast cancer. We have separate information on goserelin for prostate cancer.

HOW DOES GOSERELIN WORK?

Hormones are substances produced naturally in the body. These act as chemical messengers and help control the activity of cells and organs. Hormone therapies interfere with the way hormones are made or formed in the body.

Many types of breast cancer depend on the hormone estrogen to grow. This type of breast is called estrogen receptor-positive (ER-positive) breast cancer.

Before menopause, almost all of a woman's estrogen is made by the ovaries. Goserelin stops the ovaries from producing estrogen.

WHEN IS GOSERELIN GIVEN?

Goserelin is used to treat women who have ER-positive breast cancer and have not reached menopause. It can be used after surgery to lower the chances of the cancer returning. In these situations, goserelin is often given for two years, although the treatment can sometimes last longer.

Goserelin can also be used to halt and control the growth of breast cancer that has spread to other parts of the body (advanced or metastatic cancer). The treatment can be continued as long as it is effective in controlling the cancer.

HOW IS GOSERELIN ADMINISTERED?

Goserelin is injected under the skin (subcutaneously), normally in the stomach area. It is usually given every four weeks.

Some people may find the injection to be a bit uncomfortable and notice reddening or a dark discoloration around the area. You may have a local anesthetic cream applied before the injection to reduce any discomfort.

POSSIBLE SIDE EFFECTS OF GOSERELIN

Here, we explain the most common side effects of goserelin. You may experience some of the side effects mentioned here, though it is rare for a patient to have all of them. If you are taking other drugs, you may have certain side effects that are not listed here.

Always inform your doctor or nurse of the side effects you experience. They can prescribe drugs to help control them and can also give you advice on managing side effects.

MESTRUAL CHANGES

Women who are taking goserelin usually find that their period stops during the treatment. This is expected and is due to low levels of estrogen in the body. When goserelin is discontinued, women normally find that their period comes back. However, if a woman is approaching menopause when the treatment begins, their period may not come back after the treatment is finished.

Although women's periods tend to stop, goserelin is not a contraceptive drug. You will need to be sure you are using an effective contraceptive method while taking goserelin.

TUMOR FLARE

If you have advanced breast cancer, the symptoms caused by the cancer may get worse for up to two weeks after having the first dose of goserelin. This can happen because the levels of estrogen may temporarily rise before dropping to very low levels. Tell your doctor if this is a problem.

HOT FLASHES

These are common. Hot flashes and sweating can subside after the first few months. It can help to lower your intake of nicotine, alcohol, and hot beverages containing caffeine such as tea and coffee. Dress in layers so you can remove clothing if you need to. Natural fabrics such as cotton may be most comfortable.

Tell your doctor if your hot flashes become bothersome. Low doses of certain antidepressants can help reduce hot flashes.

LOSS OF SEX DRIVE (LIBIDO)

Many women have a reduced sex drive when taking the drug. This usually continues throughout the time the treatment is being administered. Some women also experience vaginal dryness. Lubricants can help relieve this. Your doctor or nurse can go over this with you.

VAGINAL BLEEDING

Some women have vaginal bleeding during the first weeks of taking goserelin. Tell your doctor if this continues to be the case.

SKIN RASHES

You may develop a mild skin rash. Let your doctor or nurse know if this happens. It is very important that you contact your doctor immediately if you develop a severe rash.

CHANGES TO YOUR HAIR

Some women notice that their hair thins out while they are taking goserelin. This is normally mild. Your hair normally recovers its thickness after the treatment ends.

MOOD CHANGES

Some women feel low or have other mood changes while taking goserelin. Talk to your nurse or doctor if you experience these changes so that they can give you support and advice.

HEADACHES

Let your doctor or nurse know if you have headaches. Normally, this can be easily controlled with drugs.

JOINT PAIN

You may have pain or stiffness in the joints while taking goserelin. Let your doctor or nurse know if this happens. They can prescribe painkillers and give you advice. Getting regular physical activity and keeping a healthy weight can help reduce joint pain and maintain flexibility in your joints.

BONE THINNING (OSTEOPOROSIS)

You may have a higher risk of developing osteoporosis if you are taking goserelin. Your specialist will advise you about how this can be controlled or treated.

TINGLING IN THE FINGERS AND TOES

Goserelin can cause changes in the sensitivity of your hands and feet. This is normally mild. Let your doctor or nurse know if you have this.

WEIGHT GAIN

Some women find that they put on weight more easily when taking goserelin. Eating a healthy, balanced diet and staying physically active can help you control your weight.

ADDITIONAL INFORMATION ON GOSERELIN

DELAYING AN INJECTION

If an injection is delayed for 2 to 3 days, it should not make much of a difference. However, it is important to remember that the benefits of injections are designed to happen over a period of four weeks, making it important to have injections with the greatest regularity possible.

CONTRACEPTION

It is not advisable to become pregnant while taking goserelin, as the drug can harm developing babies. It is important to use an effective method of contraception while undergoing treatment with this drug.

OTHER DRUGS

Goserelin can interact with other drugs. This includes medications that can be purchased in a store or pharmacy. Tell your doctor if you are taking any drugs, including complementary therapies, vitamins, and herbal remedies.

MEDICAL TREATMENT

If you have to go to the hospital for whatever reason other than cancer, always tell the doctors and nurses that you are taking goserelin. Explain to them that you are undergoing hormone therapy that no one should stop or restart if it is not done under the advice of a cancer doctor.