February 2017 Ask the Expert: Heart Health
Breast cancer treatments can save lives. But they can also have side effects. One serious potential side effect of some breast cancer treatments is heart damage. But you and your healthcare providers can take action to protect your heart.
In February, Living Beyond Breast Cancer expert Gretchen G. Kimmick, MD, MS answered your questions about heart health, including how different breast cancer treatments can affect your heart, how to keep your heart strong after a breast cancer diagnosis, and more.
Remember: we cannot provide diagnoses, medical consultations or specific treatment recommendations. This service is designed for educational and informational purposes only. The information is general in nature. For specific healthcare questions or concerns, consult your healthcare provider because treatment varies with individual circumstances. The content is not intended in any way to substitute for professional counseling or medical advice.
If you had an anthracycline, such as doxorubicin (Adriamycin), or the targeted therapy trastuzumab (Herceptin), there is a small increased risk of weakening of the heart muscle, also called congestive heart failure (CHF). We generally monitor heart function during therapy with trastuzumab. If you have completed therapy and had one of these medicines, it would be reasonable to check heart function with an echocardiogram every 5 years.
But at this point there is no data to support that any monitoring is worthwhile, so your doctor may simply monitor for symptoms of decrease in heart function. Symptoms that would raise concern for CHF include swelling in the legs, inability to sleep flat on your back in bed, waking at night short of breath and having to sit up, decrease in exercise tolerance or shortness of breath.
Doxorubicin (Adriamycin) can cause injury to the heart muscle, which may lead to congestive heart failure (CHF). The higher the cumulative dose of doxorubicin, the higher the risk for CHF. In early-stage disease, we typically limit cumulative dose to less than 300 mg/m2. In settings where treatment is controlling incurable cancer, the balance between the treatment side effects and cancer’s side effects need to be carefully weighed. If the treatment is working and there are no symptoms of CHF, the benefits are outweighing the risks!
If the heart is included in the area of the body being radiated, there can be scarring of the heart muscle and hardening of the arteries. The severity depends on the dose of radiation to the heart and the duration of time after the radiation. The risk is decreased by minimizing the heart’s exposure to radiation with newer radiation techniques, such as the “breath-hold” technique when radiation is given to the left breast to prevent cancer recurrence after breast conserving surgery.
At this point, we are still building evidence to support that lifestyle changes make a difference in side effects from breast cancer treatment. But lifestyle changes certainly make a difference to heart health in general. So, we suggest a healthy diet, such as the Mediterranean diet, and regular exercise, according to the American Heart Association (AHA) guidelines. The AHA guidelines recommend at least 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise (or a combination of moderate and vigorous activity). Research shows that you can even experience benefits if you divide your time into two or three segments of 10 to 15 minutes per day. You should also see your primary care provider to have your blood pressure, blood glucose, and cholesterol monitored and managed.
In the setting of metastatic breast cancer, where treatment is controlling incurable cancer, the balance between the treatment side effects and cancer’s symptoms are carefully weighed. If the treatment is working and there are no symptoms of CHF, the benefits are outweighing the risks!
If treatment includes chemotherapy or other therapies that can hurt the heart, then your doctor will carefully monitor for symptoms of decline in heart function. Your doctor may check the heart or have you see a cardiologist to consider starting medicines that would prevent decline in heart function, so you stay in better shape for longer. There is also a medicine, called dexrazoxane (Zinecard), that can protect the heart and decrease heart toxicity from anthracyclines, so you can continue to take anthracyclines for longer without them causing heart problems.
It would not be unreasonable for you to meet a cardiologist, but we are still in the process of determining which patients need to see and be monitored by a cardiologist and which patients do not.
Yes! Your cancer doctor is familiar with the side effects of breast cancer treatments and their effects on the heart. The long-term benefits and risks, based on information learned from large clinical trials, are considered in all treatment recommendations. Also, cancer doctors are increasingly recommending a healthy diet and exercise to improve overall health and well-being. These lifestyle changes most certainly make a difference to heart health and we are gathering data from clinical trials to see if it makes a difference to breast cancer outcomes.
It is very unlikely that radiation caused atrial fibrillation (AFib). In fact, this association has not been reported.
So, if you picture radiation from breast cancer, given across the chest wall, you can see how radiation to the left chest wall/breast might include part of the heart. Right breast radiation is unlikely to include meaningful exposure to the heart.
Yes, but this is a very complicated question. The cause of death, such as breast cancer or other causes, depends on the stage and type of breast cancer, the number and type of other coexisting diagnoses, called comorbidities, including heart disease, and many other factors. We do know that the risk of heart failure is related to genetic factors, as well as the effects of certain chemotherapies and radiation therapy. We also know that survival from breast cancer is improving and women are living long enough that we are now seeing heart disease as a more common cause of death than breast cancer, especially in women who have had early-stage breast cancer.
Ejection fraction, or EF, is usually now measured by a test called an echocardiogram. With echocardiograms, the cardiologist studies the heart images and measures the volume of the heart when it fills with blood and then the volume when it pushes the blood out, or contracts. The difference in these two is called the EF, given as a percentage. So, if your heart pumps to half its volume, the EF is 50 percent. Normal EF is 50-55 percent or greater. The exact number can vary with dehydration, slow or fast heart rate, and other things. To make it even more complex, there is probably a margin of error of 10 percent in either direction, so if we get a reported EF of 60 percent, it may be between 50 and 70 percent.
As far as we know, there are not any supplements that help heart health during cancer treatment. We know that some supplements may interfere with cancer treatment though, so please consult your doctor or check out the “About Herbs” online resource from Memorial Sloan Kettering Cancer Center.