Can cancer radiation damage the heart?

Dear Dr. Roach: I am a 66-year-old woman who had early-stage breast cancer and routine sessions of radiation after a lumpectomy. Everything went very well. Less than two years later, I had a mild silent heart attack. My high blood pressure has been checked routinely and controlled with medicine, in later years. I’ve never had high cholesterol or diabetes. My parents never had any blood pressure or heart issues, but both were diabetic.

I recently read that breast cancer radiation may cause heart attacks. The article also mentioned that it may be beneficial to be on heart medication as a preventive measure during breast care and radiation. Can you give more information on this subject, as it was never mentioned prior to my radiation treatments? — T.B.M.

Radiation to the heart can cause damage to the blood vessels, predisposing them to develop blockages. The risk of this is relatively small — about 1 percent of women who get radiation to the heart as part of their treatment for breast cancer will develop blockages, compared with women who don’t get radiation. The higher the dose of radiation, the greater the risk, although modern radiation techniques use far less radiation to the heart than was used a decade or two ago. Because the benefit from radiation in preventing recurrence is greater than the increased risk of developing heart disease, radiation is recommended for some women based on individual situations.

However, you are quite right that it might be wise in some situations to use medication to prevent heart disease. It’s also particularly important for those with a history of chest radiation to improve their heart health as much as possible with good diet, regular exercise, not smoking and managing high cholesterol, high blood pressure and diabetes, if appropriate.