Cardio-oncology: Emerging field focuses attention on preventing heart damage

Illustration of a human heart glowing inside the body
It’s a common conundrum faced by cancer doctors: Many of the treatments they use to fight cancer may do their job well, but at the same time, they may cause serious damage to the heart.

It’s a common conundrum faced by cancer doctors: Many of the treatments they use to fight cancer may do their job well, but at the same time, they may cause serious damage to the heart. Radiation therapy, for example, has been linked to an increased risk of heart attacks, heart failure and arrhythmias, and certain chemotherapy drugs carry a risk of hypertension and blood clots. Damage to the heart is often serious, but its effects may not show up for years after cancer treatment ends. In an effort to mitigate the danger, oncologists are increasingly working with cardiologists and primary care physicians to prevent and manage cardiac complications that may result from cancer treatments. This burgeoning partnership has become so influential that it has developed into an important medical specialty, called cardio-oncology.

Our goal is to treat patients' cancer while protecting them from serious side effects. We never want to cause life-threatening cardiovascular disease later in life.” - Anthony Perre, MD - Chief of the Division of Outpatient Medicine at Cancer Treatment Centers of America

What is cardio-oncology?

Cardio-oncology involves three main areas of focus: identify high-risk cancer patients, prevent damage to the heart and monitor patient progress. Before cancer treatment begins, oncologists consult with a cancer patient’s primary care physician and/or cardiologist to identify chronic conditions, such as hypertension and diabetes, that increase the patient’s risk for cardiovascular issues. The information is then used to guide the patient’s treatment plan and dictate which therapies are prescribed, Dr. Perre says. Doctors also work together to recommend prevention-based lifestyle changes, such as diet or exercise regimens designed for weight loss or cessation programs to help patients quit smoking, to help lower their risk for heart disease. Once cancer treatment begins, the cardio-oncology team monitors how certain therapies may be affecting the patient’s heart, making adjustments as necessary.

In the past, doctors used an echocardiogram to measure changes in the heart’s ability to pump blood, since lower rates may be a sign of treatment-related heart damage. Today, though, doctors may use a technology called strain imaging to determine whether a treatment is likely to cause complications before signs of heart damage even develop. Such technological advances are helping to expand the options available to reduce patients’ risk of cardiac issues, even though the challenge remains difficult, Dr. Perre says. “Unfortunately, we’re seeing more heart risk from cancer treatments than ever before,” he says. “But we can’t stop the treatments because they’re working well to fight the cancer.”

Making strides

One reason behind the increase in heart risk: the recent wave of targeted therapy drug approvals by the U.S. Food and Drug Administration. “These drugs are helping us make strides in the fight against cancer,” Dr. Perre says. “But many of them, like trastuzumab (Herceptin®)—commonly used to treat breast cancer—may affect the heart by reducing its pumping ability, which could lead to congestive heart failure.” Another factor is the rising number of people living with cancer well beyond treatment. In 2016, the number of cancer survivors living in the United States reached nearly 15.5 million, and that record is expected to hit 19 million by 2024. While they’ve survived cancer, these patients may have cardiovascular issues later in life because of damage caused by their cancer treatments.

As a cancer survivor, Dr. Perre knows his cardiovascular risk is higher than the average person’s. To treat his Hodgkin lymphoma, Dr. Perre was given a combination of radiation therapy and doxorubicin (Adriamycin®), a drug that damages cancer DNA but also carries the potential for heart disease later in life. “I know I’m at a greater danger for heart problems,” he says. “That’s why I have to make sure I take the precautions I can and undergo the proper monitoring.  Prevention and vigilance are such important components of cardio-oncology.”