Some treatments for breast cancer may increase the risk of getting heart problems, usually many years later. You will have been monitored closely during and after treatment to reduce the risk of this happening. Most women won’t ever experience any effects on the heart. But it may help to understand more about them and how you can help look after your heart.
The most important risk factor for developing future heart problems is pre-existing heart disease, including high blood pressure. Women at risk are carefully monitored before and during their treatment to find out if their treatment needs to be changed. Many women who have these drugs won’t ever experience heart problems.
The standard chemotherapy for early breast cancer usually includes drugs known as anthracyclines, for example epirubicin or doxorubicin. This is an effective treatment for breast cancer as evidence shows that these drugs are good at reducing the risk of it coming back.
In a small number of women, treatment with anthracyclines may result in slight damage to the heart muscle. Because these changes are slight, they usually don’t cause any immediately noticeable effects. But they may lead to an increased risk of heart problems developing much later in life.
After radiotherapy to the chest, there is a very small risk of damage to the heart muscle or the major blood vessels around the heart. This is only a potential problem if you’ve had cancer in your left breast, as the heart is on the left side of the chest. Radiotherapy is now very carefully planned, so that the heart is either outside the radiation area completely, or only a small part of the heart will receive any radiation. As a result, the risk of developing any heart problems is now very low.
An early menopause
Having an early menopause due to your treatment may also increase the risk of heart problems. This is because oestrogen and progesterone help protect the heart. Hormonal drugs, called aromatase inhibitors, may also increase the risk of high cholesterol, which can lead to heart problems.
Trastuzumab (Herceptin) can cause changes in the way the heart functions, particularly in women who already have heart disease. Because of this, it’s not given to women with some types of heart condition. Tests are done before treatment and women are checked regularly throughout and after treatment.
If heart problems occur during treatment with trastuzumab, they are usually temporary, improve with medication and get better after treatment finishes.