The possible benefits of treatment vary; for some people hormonal therapy may reduce the risk of cancer coming back, for others it may control the cancer and its symptoms. Your clinical team will be happy to answer any questions you have about your treatment.
Hormones are substances produced naturally in the body. They act as chemical messengers and help control the activity of cells and organs. Hormonal therapies are drugs that interfere with 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.
In women, after the menopause, oestrogen is no longer made in the ovaries. Instead, it is made in the fatty tissues of the body. This happens when an enzyme (a type of protein) called aromatase changes other hormones into oestrogen. Exemestane is a type of drug called an aromatase inhibitor. It blocks (inhibits) the activity of aromatase and reduces the amount of oestrogen in the body. This means that cancer may grow more slowly or stop it growing altogether.
Exemestane may also be used in men, patients who were assigned male at birth, or in patients who have not gone through the menopause. In this case, exemestane will be combined with goserelin or leuprorelin injections.
Your treatment
Exemestane tablets are taken once a day continuously until your clinical team tells you otherwise. Take it after food. Try to take it at the same time each day, morning or evening.
You may take exemestane after surgery and with other treatments to reduce the risk of breast cancer coming back. You will usually take it for a few years. Doctors sometimes prescribe it before or after you have another type of hormonal therapy drug, to control breast cancer that has spread to other parts of the body (secondary breast cancer).
If you feel unwell, you have symptoms of an infection or your temperature is 37.5ºC or above, or below 36ºC, contact The Christie Hotline straight away.
Possible side effects
Hormonal therapy can cause different side effects. Some are more likely to occur than others. Everyone is different and not everyone gets all the side effects. Most side effects are usually temporary, but in some rare cases they can be life-threatening. It is important to tell your clinical team about any side effects so they can be monitored, and where possible, treated.
Common side effects (more than 1 in 10 people)
Hot flushes
Hot flushes and sweats may occur but do lessen after the first few months. Cutting down on nicotine, alcohol and hot drinks containing caffeine, such as tea and coffee can help. Dress in layers, so you can remove clothes as needed. Natural fabrics, such as cotton may feel more comfortable. If hot flushes are a problem, tell your clinical team.
Many of the over-the-counter preparations that can be bought for menopausal symptoms are not suitable for patients with a history of breast cancer. Please consult your medical team before starting any new medication or herbal supplements. Low doses of certain antidepressant drugs can help to reduce flushes.
Joint and muscle pain
You may have pain and stiffness in your joints, and sometimes in your muscles while taking exemestane. Let your clinical team know if this happens. They can prescribe painkillers and give you advice. Being physically active and maintaining a healthy weight can help reduce joint pain and keep them flexible.
Sickness and diarrhoea
Any sickness is usually mild, but let your clinical team know if this happens. Exemestane may also cause indigestion or tummy pain. Let them know if you have any of these symptoms. They can prescribe drugs to help.
If diarrhoea becomes a problem during or after your treatment, anti-diarrhoeal tablets can be prescribed by your clinical team. Ask the staff for a copy of The Christie booklet 'Eating, help yourself' which has useful ideas about diet when you are having treatment.
Fatigue (tiredness)
You may feel tired, sleepy or feel like you have no energy when you start taking exemestane. Try to pace yourself until this improves. It's important to get the right balance of having enough rest and being physically active. Regular short walks will help you to feel less tired. If you feel sleepy, don't drive or operate machinery.
Headaches and dizziness
If you have headaches, let your doctor or nurses know. They can usually be controlled with painkillers you can buy yourself. Exemestane may cause dizziness. Let your clinical team know if this is a problem.
Insomnia and mood changes
Some people may have problems concentrating, feel anxious or have difficulty sleeping while taking exemestane. If you have trouble getting to sleep, try having a warm bath or a hot milky drink before bed. Relaxation techniques, CDs, apps and audio guides can also help. Some people may feel low in mood or become depressed while taking exemestane. Talk to your GP if this happens. They can suggest ways to help with this.
Hair thinning
Your hair may become thinner while taking exemestane. This is usually mild. Your hair will return to normal after treatment finishes.
Changes in the way your liver works
Exemestane may cause changes in the way your liver works. You are very unlikely to notice any changes. Your clinical team will take regular blood samples to check your liver is working properly.
Rarely, exemestane causes inflammation of the liver (hepatitis). Tell your clinical team straightaway if the whites of your eyes or your skin turns yellow, or if you become unwell with itching, or pain on the right side of your stomach.
Reduced white blood cells
Exemestane can reduce the number of white blood cells in your blood. these cells fight infection. If you have any signs of infection, tell your GP or cancer team.
Uncommon side effects (less than 1 in 10)
Pain, numbness and tingling in hands and fingers
These symptoms may be due to carpal tunnel syndrome which is caused by pressure on a nerve in the wrist. It is more common in people taking exemestane. Tell your clinical team if you have these symptoms.
Skin rash and dry skin
You may get a mild skin rash. Tell your clinical team if this happens. It is very important to contact your clinical team straightaway if you get a severe skin rash.
Bone thinning
Taking exemestane for a few years increases your risk of bone thinning, called osteoporosis. This can increase your risk of a broken bone (fracture). You will usually have a bone density scan to check your bone health before and during treatment.
If you are at risk of osteoporosis, your clinical team may prescribe drugs called bisphosphonates to protect your bones. They will also usually advise you to take vitamin D supplements (20 micrograms or 800 international units minimum daily dose). Calcium supplements are rarely necessary as most patients have an adequate dietary intake of calcium. Regular walking, eating a healthy diet, not smoking and sticking to sensible drinking guidelines will also help to strengthen your bones.
Fluid build-up
You may put on weight or your ankles and legs may swell because of fluid building up. Tell your clinical team if this happens. If your ankles and legs swell, it can help to put your legs up on a foot stool or cushion.
Bruising or bleeding
This treatment can reduce the production of platelets which help the blood clot. Let your clinical team know if you have any unexplained bruising or bleeding such as nosebleeds, bloodspots or rashes on the skin, and bleeding gums.
Constipation
You may become constipated. Try to drink plenty of fluids and eat foods high in fibre. Tell your clinical team who may prescribe a suitable laxative. Please contact The Christie Hotline if your constipation lasts more, 3 days or you experience abdominal discomfort.
Appetite and weight change
If you don't have much appetite, try eating small frequent meals or snacks. If problems with eating don't get better, talk to your GP.
Sex, contraception and fertility
Exemestane is usually used when you have been through the menopause. However, if you have recently been though the menopause, had a chemotherapy induced menopause or are having treatment to stop your ovaries working there is still a small chance that you could become pregnant. It is important not to get pregnant while having this treatment as this drug may harm a developing baby. If you are sexually active you must use effective contraception while taking exemestane.
Flu vaccinations
We advise that all patients receive a flu vaccination when this is offered. However, if you are thinking of having any other vaccines, check with your clinical team first, because some vaccines should be avoided.
COVID-19 vaccinations
We advise that all patients receive a COVID-19 vaccination when this is offered.
Other medicines
Some medicines and herbal remedies may interact with exemestane. Please consult your doctor or pharmacist if you are starting any new medications.
Contacts
If you have any general questions or concerns about your treatment, please ring your consultant's secretary or breast cancer nurse.
For urgent advice, please ring The Christie Hotline on 0161 446 3658 (24 hours a day, 7 days a week).