Learn about the most commonly associated medications and how BCRF research is helping at-risk patients
Key Takeaways
- Cancer treatment can cause heart problems, a side effect known as cardiotoxicity.
- About 5-15% of breast cancer patients develop some form of cardiotoxicity, which can include heart failure, arrhythmia, and muscle damage.
- As treatments have improved, cardiotoxicity has become less commmon.
- Frequent monitoring as well as practicing heart-healthy behaviors can mitigate the risk.
Cancer treatments can cause a variety of side effects. One is heart damage, which is known as cardiotoxicity. BCRF researcher Dr. Dawn Hershman studies side effects of cancer treatment, including cardiotoxicity, and shares what every patient should know.
How common is cardiotoxicity?
About 5-15% of breast cancer patients develop some form of cardiotoxicity. Women have a higher risk of dying from cardiovascular disease due to shared risk factors as well as long term effects of treatments Thankfully, cardiotoxicity is decreasing in frequency as treatments have changed.
What kinds of cancer treatments impact the heart?
Cardiotoxicity was originally most commonly associated with a drug class of chemotherapies that included Adriamycin (doxorubicin). The higher the dose given over time, the higher the risk. The other drugs that have been associated are some of the antibodies that treat HER-2 positive cancers, such as trastuzumab and pertuzumab. Other treatments, such as radiation to the left side of the chest, can also increase the risk.
Are there any drugs that are less cardiotoxic than others?
There are many newer treatments that may have fewer cardiac effects, and the goal is always to increase efficacy while reducing toxicity. Newer treatments can sometimes cause other heart issues, though. For example, some of the newer immunotherapy drugs, such as pembrolizumab, can cause inflammation to the heart muscle. Other drug classes, such as CDK4/6 inhibitors, can cause arrythmias. It is important to monitor people with electrocardiograms (EKGs) initially to make sure the medications are not causing any changes. In addition, it is important to check to make sure they are not interacting with others that can also cause this problem.
Do all treatments impact the heart in the same way?
Some drugs affect the muscle and reduce the way the heart pumps blood. Some affect the electrical system and can cause problems with the heart rhythm. Some can cause inflammation. Some treatments such as radiation can affect the coronary arteries and increase risk of a heart attack. But all of these side effects are rare.
When does cardiotoxicity tend to appear?
It can show up at any time during treatment. Very rarely, toxicities can show up late, even years after treatment is complete. This happens much less frequently now, though.
What are the symptoms of cardiotoxicity?
The most common symptom for weakening of the heart muscle is shortness of breath with any exertion that is worsening over time. The best test is an echocardiogram (an ultrasound of the heart) to help make sure the muscle is working properly.
What can be done to prevent cardiotoxicity?
The best strategies to date have been frequent monitoring to avoid complications and discontinuing treatments if toxicities develop. As with the general population, managing cardiovascular risk factors with diet, exercise, weight optimization, smoking cessation, limited alcohol, and medications is also an important preventive measure.
The initial strategy to reduce risk was to decrease the number of cycles of doxorubicin and the total lifetime dose. More recently, other treatments have been given instead to replace it with less risky treatments. Since the antibodies that treat HER-2 positive cancer can exacerbate heart damage when taken with anthracyclines, the strategy has been to develop treatments where they are not given together.
Are certain people more at risk of cardiotoxicity than others?
Some people can be at higher risk if they have underlying untreated high blood pressure or other cardiac risk factors. Patients should let their doctor know about pre-existing heart conditions and any medications they are on, plus risk factors such as high blood pressure, high cholesterol, and diabetes. This may influence how frequently the person is undergoing screening evaluations of the heart — and may even influence the choice of treatment.
What is your BCRF-funded research showing us about cardiotoxicity?
Some of our BCRF funded work has looked at the relationship between pre-existing cardiac risk factors and other health conditions to help predict who may be at highest risk for complications to better guide care. In addition, we have also found that many patients are prescribed medications that may interact with medications they are taking. This has led to more efforts to work with pharmacists to better identify drug interactions and alternative strategies.
Can cardiotoxicity be reversed?
Yes. Sometimes, with frequent monitoring, the medications can be stopped and the damage reverses. This monitoring has improved over time so that early changes can inform treatment decisions.
