Heart health and cancer

Some cancer treatments can affect how your heart works. This may cause heart problems that are either short-term (temporary) or long-term (permanent).

Problems may develop during or soon after cancer treatment. Some problems may develop many years later. These are called late effects.

The risk of heart problems depends on the type of cancer treatment you have and how much treatment you have.

Your risk may be higher if:

• you have other risk factors for developing heart problems
• you had a heart problem before starting cancer treatment
• you have several cancer treatments at the same time.

Your cancer doctor will explain if a cancer treatment is likely to affect your heart. If you are worried about heart problems, ask them for more information.

Cancer treatment in childhood

If you had cancer treatment as a child, you may have a higher risk of developing heart problems as an adult. This depends on the type of cancer treatment you had.

If you are looking for information about late effects of cancer treatment in childhood or as a teenager, you might find the following information helpful:

• Teenagers and Young Adults with Cancer – Late effects
• Teenage Cancer Trust - Late effects of cancer treatment
• Children’s Cancer and Leukaemia Group – I had cancer as a child

Different cancer drugs and treatments can affect heart health in different ways and at different times. We have some general information on this page. But if you need information about possible side effects of a specific drug, you can:

• search our A-Z of cancer treatments
• visit the electronic Medicines Compendium (eMC).

Chemotherapy

Some chemotherapy drugs may cause:

• high blood pressure
• abnormal heart rhythms called arrhythmias
• symptoms of angina or heart failure
• inflammation or damage to the muscle of the heart
• increased risk of developing other health problems, such as diabetes.

Some chemotherapy drugs are given into a vein (intravenously) with large amounts of fluid. If you already have a heart condition, this can put pressure on your heart and may cause problems. Your nurse will monitor you for any signs of problems while you have these treatments.

Some drugs are only likely to cause heart problems if you have a high dose. Your cancer doctor will plan your treatment carefully and record the doses you are given.

Some may cause heart problems during or shortly after treatment. Others can cause heart problems many years later. These are called late effects.

Targeted therapy and immunotherapy drugs

Some targeted therapy and immunotherapy drugs can affect the heart. Some drugs may cause high blood pressure or abnormal heart rhythms. Others can damage the muscle of the heart or cause symptoms of angina or heart failure.

These types of side effect may happen during or soon after treatment. Sometimes they happen months after treatment finishes. Side effects that happen after treatment finishes are called late effects.

Researchers are still looking at the effect some of these newer drugs have on heart health. Your cancer doctor, specialist nurse or pharmacist will talk to you about the drug you are having. They will explain any risks before you start treatment.

Hormonal therapy drugs

Hormonal therapies do not usually damage the heart directly, but they can affect your risk of heart problems. They may:

• raise your blood pressure or cholesterol levels
• cause weight gain, which may increase your risk of developing diabetes and heart problems in the future
• cause an early menopause – the risk of heart problems increases after the menopause.

Some people who take hormonal therapies for many years to treat prostate cancer can also have a higher risk of early heart failure. If you are taking a hormonal therapy drug, you can reduce these risks by making healthy lifestyle changes. Your doctor may also suggest treatments for high blood pressure or high cholesterol.

Surgery

Surgery is one of the main treatments for cancer. Sometimes surgery can put the heart under stress and cause heart problems. Having a general anaesthetic to keep you asleep during surgery may also cause heart problems for some people.

If you have a healthy heart, surgery is not usually a problem. But there may be a higher risk of damage to the heart for people who:

• had heart problems before surgery
• have diabetes
• are over 70 years old
• have high blood pressure 
• smoke
• are overweight.

If you have minor surgery and only need to be asleep (anaesthetised) for a short time, the risk may be small. If you have major surgery and need to be asleep for several hours, the risk can be greater.

Your cancer doctor will talk to you about the possible risks of your surgery. Before you have a general anaesthetic, you will have heart tests. These are to check your heart and make sure you are fit enough for surgery. If you have a high risk of serious heart problems, your doctor may suggest other cancer treatments you can have instead.

Radiotherapy

Most people do not develop heart problems due to radiotherapy treatment. If you have radiotherapy to another part of your body, away from the heart, it is unlikely to damage the heart.

But radiotherapy may cause heart problems if given near the heart. Treatment can usually be planned and delivered to avoid affecting the heart. Modern radiotherapy techniques are very accurate. This means heart problems after radiotherapy are rare.

What heart problems are possible after radiotherapy?

Rarely, radiotherapy to the heart can:

• cause scarring or thickening of the coronary arteries, which can lead to coronary heart disease (CHD)
• cause inflammation of the protective sac called the pericardium that covers the heart – this is called pericarditis
• cause a build-up of fluid between the inner and outer layers of the protective sac called the pericardium that covers the heart – this is called pericardial effusion
• damage the heart muscle
• damage the heart valves
• affect the heart’s electrical system and cause an abnormal rhythm. This is called an arrhythmia.

What is the risk of heart problems after radiotherapy

The risk of damage to the heart depends on:

• the total dose of radiotherapy given
• how much of the heart is in the treatment area.

The higher the overall dose of radiotherapy and the amount of the heart exposed, the greater the risk of damage. But the risk is still very small.

The risk of heart damage also increases if:

• you are having chemotherapy at the same time
• you already have a heart condition.

What is deep inspiration breath hold technique?

To protect the heart during radiotherapy to the left side of the chest, doctors use a technique called deep inspiration breath hold (DIBH). This means they ask you to breathe in deeply and hold this breath while they give you the radiation. The air in your lungs can help to reduce the amount of radiation the heart is exposed to. The website Respire explains more about DIBH.

Heart health follow up after radiotherapy

Heart problems can sometimes happen during treatment. Or they may develop months or many years later (late effects).

If you were told the radiotherapy may affect your heart, you can reduce the risk by making healthy lifestyle choices.

Some people have regular appointments after cancer treatment to check for signs of heart problems. At the appointments, you may have:

• your blood pressure checked
• a blood test to check your cholesterol levels
• scans to check how your heart is working.

If you notice any warning signs of heart problems, tell a doctor as soon as possible.

Cancer research trial (clinical trials)

Your cancer doctor may talk to you about having cancer treatment as part of a clinical trial. Clinical trials test new treatments or new ways of giving treatments.

Before you decide if you want to take part, your doctor or a clinical researcher will explain the trial. They will give you information about any known side effects of the treatment.

They may not know all the effects these treatments have on the heart. If you join the trial, you will be monitored closely for side effects.

If you develop heart problems during or after cancer treatment, your cancer doctor will talk to you about the best way to manage them. This might involve:

Changes to your cancer treatment

If you are having cancer treatment when the heart problem starts, your cancer doctor may suggest changing your treatment to prevent further damage. These changes may include:

• stopping cancer treatment for a time
• lowering the dose
• changing to a different treatment that is less likely to cause heart problems
• stopping cancer treatment completely.

Treatment for the heart condition

Your cancer doctor may arrange for you to see a heart doctor (cardiologist) for advice. Some heart problems may be managed and monitored by your GP. Your cancer doctor, GP or heart doctor (cardiologist) will explain if you need treatment for the heart condition.

Follow-up appointments

You may have regular follow-up appointments to check your heart health after cancer treatment. Your cancer team or GP can explain what to expect.

Pregnancy and giving birth can put pressure on your heart. If you are thinking about becoming pregnant after cancer treatment, you should ask your doctor for advice.

Your doctor may arrange for you to see a heart doctor (cardiologist). They can give you specialist advice before or during your pregnancy. You may also have extra tests to check your heart health while you are pregnant.

Cancer can be stressful for lots of reasons. You may be dealing with some difficult emotions, worrying about the future, and coping with treatment and side effects.

Stress can raise your blood pressure and put more strain on your heart than usual. Smoking, drinking alcohol or over-eating to cope with stress can also increase the risks to your heart.

If you already have a heart condition, feeling extremely stressed or anxious can sometimes cause symptoms such as angina.

It is important to find healthy ways of coping with stress. The British Heart Foundation has information about heart health and coping with stress. And there is further information about coping with stress on the NHS Moodzone website.

If you need to talk, you can:

• call the Macmillan Support Line free on 0808 808 00 00
• chat to our specialists online
• visit our Online Community to talk to people who have been affected by cancer, share your experience, and ask an expert your questions.

The British Heart Foundation has more information about how to keep your heart healthy.