Keeping Your Heart Healthy

Treating childhood cancer requires strong medicine. Cancer treatments are carefully designed to maximize the chance for cure while minimizing the possibility of developing health problems later due to the medications - but these problems can happen. At City of Hope's Childhood Cancer Survivorship Clinic, we aim to help survivors stay as healthy as possible. Survivors who come to the Survivorship Clinic get screening tests regularly so that if any problems occur, they're picked up early, when they're easiest to treat.

Two treatments that can affect the heart are certain chemotherapy medications and radiation therapy. Medications called anthracyclines have been used to treat many kinds of childhood cancer for decades. Doxorubicin (Adriamycin®), daunorubicin (daunomycin, Cerubidine®) and idarubicin (Idamycin®) are some of the more common anthracyclines. Radiation to the chest area is also used to treat many childhood cancers.

While anthracyclines and chest radiation are instrumental in curing many childhood cancers, they also sometimes can damage healthy cells, including the cells in heart muscle. That's why doses of anthracyclines and chest radiation are carefully measured during treatment and kept as low as possible. This provides the best chance for cure while limiting the chance of developing future heart problems.

Most people treated with anthracyclines and/or chest radiation as children, teens or young adults don't develop heart problems after treatment. It is important for survivors to be aware of the risks, though, and to take steps to keep the heart healthy and strong.

In a healthy heart, the muscle contracts and relaxes regularly. When muscle cells in the heart wall are damaged, over time the muscle doesn't work as well as it used to, and the heart can't pump blood as well as it should. One of the best ways to keep the heart healthy is to get regular exercise, such as brisk walking or running. It's also important to eat a healthy diet and maintain normal body weight.

Avoiding factors that can increase the risk of developing heart problems is also an important strategy. One obvious risk to avoid is smoking, which stresses the heart and lungs. Another is heavy weight lifting. When someone lifts a very heavy weight, the heart has to pump harder as the person strains under the weight. This can be tough for the heart. Lifting lighter weights more frequently, instead of lifting a heavy weight all at once, puts less strain on the heart and is a healthier strategy. The amount of weight people can safely lift depends on their body size and level of fitness, but as a general rule, any weight that can be lifted with ease 15 to 20 times in a row causes less stress to the heart and is more likely to be safe.

Some other medical conditions that may also lead to an increase in the risk of heart disease are related to your family's health history. If diseases such as obesity, high blood pressure, high cholesterol or triglyceride levels in the blood, and diabetes run in your family, you may be at greater risk for developing these conditions. Many health behaviors will also increase the risk of heart disease. In addition to smoking and heavy weight lifting, these include a sedentary (inactive) lifestyle and eating a diet high in fat.

Survivors in the Childhood Cancer Survivorship Clinic who received anthracycline chemotherapy or chest radiation get regular heart screenings with a test called an echocardiogram. The test uses sound waves to take pictures and video clips of the heart as it beats. A technician or cardiologist then takes measurements from those images to see how well the heart is working.

Currently, many survivors attending the clinic are participating in a research study led by Saro Armenian, D.O., M.P.H. This study is designed to see if a more comprehensive evaluation can help identify early signs of heart damage from previous anthracycline chemotherapy. This evaluation involves a detailed echocardiogram and a blood test for substances called "cardiac biomarkers" that may be helpful in showing early signs of heart damage.

The echocardiogram looks at things like the thickness of the person's heart walls (to see if the muscle has gotten stretched out) and the time it takes for the muscle to relax each time the heart pumps. At the end of the study, researchers will compare the cardiac biomarker levels with the echocardiogram measurements. If the study proves that these extra measurements and blood tests are helpful, they may become a regular part of heart health screening for childhood cancer survivors.