DEAR DOCTOR K:
I had radiation therapy for breast cancer a few years ago. Now I’m reading that radiation therapy might increase my risk for heart disease. Is this true? Can I do anything to decrease my risk?
Radiation therapy uses high-energy rays to damage or destroy cancer cells. It harms cancer cells primarily by damaging their genes. But the radiation can also damage the genes of healthy non-cancerous cells.
Newer radiation techniques allow higher doses of radiation to be aimed more precisely at the area being treated. This reduces damage to healthy tissue near a tumor, but it doesn’t eliminate it completely. For example, radiation to the chest, as done during breast cancer treatment, can harm the heart muscle, arteries and valves.
I spoke to my colleague Dr. Deepak Bhatt. He is executive director of Interventional Cardiovascular Programs at Brigham and Women’s Hospital Heart and Vascular Center and editor-in-chief of the Harvard Heart Letter. He noted that in women who have had breast radiation, the lifetime risk of having a heart attack or another major cardiac event increases about 3 percent. Women who have radiation to the left breast, which is closer to the heart, have a higher chance of problems. The overall dose of radiation also plays a role.
Radiation-related heart effects can emerge as soon as five years after treatment. So women who have breast cancer at a younger age may develop heart problems earlier than would otherwise be expected.
Undergoing baseline heart tests before treatment starts can sometimes help doctors monitor you for heart changes. That way, they can be addressed quickly if they occur.
You may not be able to protect yourself completely from the long-term side effects of radiation, but you can take other steps to bolster your heart health. Here are some proven strategies to help reduce your heart disease risk:
- Avoid tobacco.
- Exercise for at least 30 minutes a day.
- Adopt a healthy eating plan. That means choosing unsaturated and monounsaturated fats instead of trans fats or saturated fats; eating more fiber; and reducing your salt intake.
- Maintain a healthy weight (a body mass index between 18.5 and 24.9).
- Control blood pressure, with medication if needed.
- Control cholesterol, with a statin if needed.
- Control blood sugar with exercise, dietary changes and medications if needed.
Both patients and doctors are frequently frustrated by the fact that a treatment that improves one medical problem can sometimes cause another. This is an example. Of course, doctors and research scientists are constantly trying to find treatments where the benefits greatly exceed the risks. But there are, unfortunately, very few treatments that have absolutely no risks.
Compared to when I was a medical student, the treatment of breast cancer — through medication, radiation and surgery — has greatly improved. Today’s treatments are both more effective and less risky. And I’ll bet that in the next few decades, the situation will improve further.