Your heart on chemo: Protecting your heart during cancer treatment

What's the connection between heart disease and cancer?

While there's no connection between these diseases, there is a connection between the medications used to treat cancer and the heart. Several drugs used to treat some of the most common forms of cancer, like breast cancer, leukemia and lymphoma, can affect how the heart functions. In some cases, this can lead to heart failure, elevated blood pressure, rapid heartbeat and heart attack.

What are some examples?

One of the drugs known to cause problems is Adriamycin. This drug has been used and studied for many years, and the risks to the heart are well known. It is generally considered to be the first line of treatment when anyone needs chemotherapy for breast cancer, lymphoma and leukemia, but it is also used to treat other cancers. People who are treated with this drug are at highest risk of developing heart-related side effects within the first year after treatment. But the tricky part is that there are often no obvious symptoms, so you may not know about it unless your doctor looks for it. Treatment with Adriamycin is associated with a two percent lifelong risk for developing heart failure.

Another cancer drug that can affect the heart is Herceptin. This is significant because Herceptin is also used to treat breast cancer, specifically those who have HER2 receptor-positive breast cancer. The combination of these two drugs, Adriamycin and Herceptin, increases the lifelong risk of heart failure to 8–30 percent.

What steps should be taken if you are being treated for cancer with these or other drugs that can affect the heart?

Oncologists are very aware of the possible side effects of treatments, and we work closely with them to evaluate and monitor patients at risk. The good news is that we know much more about how to treat heart failure than we did when some of these cancer drugs were introduced. We've learned that treating cancer patients with some of the same drugs we use to treat heart failure can prevent damage to the heart or improve their heart function if damage has already occurred.

We don't treat everyone who is receiving these medications, only those who have already experienced some changes in their heart function or who are known to be at higher risk for these side effects. That includes people over age 65 or those with a history of any kind of heart disease, including high blood pressure, coronary artery disease or heart rhythm problems. We also treat people of any age who have the BRCA gene mutation. This is an inherited mutation that increases the risk of breast cancer. For some reason, people with the BRCA mutation are at increased risk for heart problems when treated with these drugs.

It’s important to note that keeping these side effects to a minimum can help patients complete a full course of their recommended chemotherapy. That gives them a better chance for remission and ultimately curing their cancer.

What if you've been treated for cancer in the past? Is there anything to watch for?

Make sure to keep any follow-up appointments with your oncologist and primary care doctor. If you have any of the above-mentioned risk factors, ask to be referred to a cardio-oncology clinic for an initial evaluation. Listen to your body and report any symptoms of fatigue, chest pain, shortness of breath or swelling of the ankles.