Researchers at Columbia University Medical Center have discovered that certain women undergoing radiation therapy for early-stage breast cancer may have an elevated risk of developing cardiovascular disease.
David J. Brenner, PhD, DSc, of Columbia University, and his team studied treatment plans of 48 patients with stage 0 through IIA breast cancer in order to assess the risk of developing cardiovascular disease from radiotherapy. This study was first published in JAMA Internal Medicine and an article from Healio Cardiology outlines the results.
Dr. Brenner and his team found that certain radiation treatment factors led to an increased risk of myocardial infarction (heart attacks) and ischemic heart disease.
They analyzed the effect of four of these treatment factors for the study:
- Cardiac dose — The amount of radiation absorbed by the body during treatment.
- Baseline cardiac risk — Whether the patient had existing cardiac risk factors, such as elevated cholesterol levels or high blood pressure.
- Treatment side — Whether treatment was performed on the left or right side.
- Body position — If the patient was in a supine or prone position during treatment.
The data revealed that women who had left-sided radiotherapy in a supine position had the highest measured cardiac dose.
In the article, Dr. Brenner commented on these findings:
"Because the effects of radiation exposure on cardiac disease risk seem to be multiplicative, the highest radiation exposure risks correspond to the highest baseline cardiac risk." That means that women who already have several underlying cardiac risk factors such as smoking, high cholesterol or high blood pressure, are the ones who need more careful treatment.
Many physicians, such as Dr. Dan O'Connor of Columbia, recognize the need to treat underlying cardiac risk factors in patients undergoing radiation therapy.
"This article speaks to the growing body of evidence that demonstrates cardiovascular health as an important component of long-term breast cancer survivorship. The current successes of early detection, early treatment and high cure rates have changed the patient-physician discussion about the prognosis of breast cancer. Results from this article add to the framework of physician-patient discussion, including aggressive treatment of high blood pressure, high cholesterol, and smoking cessation to ensure long-term cardiovascular health to breast cancer survivors."
All breast cancer patients should also be aware of the advances made in radiation oncology since this study was undertaken. Innovative technologies, which limit the radiation-related risk for developing heart disease, are now more readily available to patients.