Today there are approximately 15.5 million adult cancer survivors in the United States, and more than 40 percent of those who are over 50 will develop cardiovascular disease. And this is good news. Why? Because cancer treatments have become more effective and patients are surviving long enough to develop these side effects.
“We used to not think of cardiac effects of cancer treatment,” says Dr. Moslehi, the director of cardio-oncology at Vanderbilt University Medical Center. “Now, because patients live longer, we know that what we do to the heart matters.”
For those who develop heart problems after cancer treatment, it is not solely caused by a particular chemotherapy agent or radiation. There are other factors at work that include – high cholesterol, diabetes, high blood pressure, a history of smoking, age, and genetics.
While there is no exact recipe for preventing heart disease, there are some steps survivors can take to decrease their risk. Knowing what watch for and what to do can help survivors keep their heart healthy and ticking long after treatment is over.
Know your cardiac risks
Different treatments can damage the heart in different ways. The top culprits include:
- Anthracyclines – While these chemotherapy agents are used in much smaller doses than in the past, they can still damage muscle cells of the heart and cause problems like left ventricular dysfunction, cardiomyopathy, and arrhythmias, that result in the heart not beating normally.
Herceptin – This targeted therapy used to treat HER2+ cancers, can cause a reduction in heart function. Frequent echocardiograms can detect this reduction, and when this treatment is stopped, the side effects are often reversed.
Radiation – Radiation to the left side of the chest can cause heart tissue to scar and stiffen and this can lead to a variety of different conditions including abnormal rhythms, heart valve problems, and problems with the membrane (pericardium) that surrounds the heart.
What to watch for
Survivors should schedule regular visits with a doctor who is aware of their cancer treatment and the possible associated cardiac risk. This doctor will schedule any necessary tests to monitor heart function. Beyond that, survivors should notify their doctors if they develop any of the following symptoms.
- Shortness of breath
- Lightheadedness or dizziness
- Chest pain or discomfort
- Extreme fatigue
- Swollen hands or feet
- Periods of heart racing or throbbing
- Periods of irregular heartbeat
Keeping your heart healthy
Heart disease and cancer share many of the same risk factors, including high cholesterol, blood pressure, and weight, as well as diabetes and smoking. Mitigating these factors is twice as important because it helps make it less likely these survivors will suffer from either disease.
One of the best ways to reduce a person’s chances of heart disease and cancer risk is exercise. But, how much? Do you need to get to the gym every day?
The American Cancer Society and the American College of Sports Medicine recommends 150 minutes of moderate exercise every week. But this may be a lot for patients who are less active or overweight.
“Getting your heart rate up for 30-40 minutes 3-4 times per week can help prevent heart disease and cancer,” Dr. Moslehi tells HealthCentral.
Dr. Gilchrist, associate professor in cardiology and cancer prevention who runs the Healthy Heart program at MD Anderson is an advocate for customizing exercise programs. “We need to individualize our exercise prescriptions,” Dr. Gilchrist says in a phone interview with HealthCentral. “Down the road, I think cancer patients will be able to benefit from prescriptions as we learn about what exactly the right amount of exercise is for each patient. We have very specific doses for drugs that we give to cancer patients, but we still have very broad guidelines about exercise even though it's a very powerful way to increase survival.”
The American Cancer Society has some tips and guidelines for cancer survivors who may be new to exercise. Group classes, especially with other people who’ve had cancer can provide good motivation.
“We’ve found,” says Dr. Gilchrist, “that the individuals most likely to change their behavior are the ones that feel connected to other survivors. So, finding an exercise group in their community made up of people who have gone through a similar experience is very powerful. They get the idea that ‘this person did it, they went through the same thing I did, and I can see the benefit they're getting from being active. I want to do that too.’” Twelve-week survivorship exercise classes are offered in 600 communities around the country through the Livestrong and YMCA.