Younger adults undergoing radiation therapy for left-sided breast cancer face a heightened risk of coronary artery disease (CAD), according to a new analysis published in JACC: CardioOncology. In fact, the authors observed, it nearly doubles the patient’s risk of CAD compared to radiation therapy for right-sided breast cancer.
The study included data from nearly 1,000 breast cancer patients who were diagnosed between 1985 and 2008. They were all under the age of 55 years old at the time of treatment. The average follow-up period was 14 years, giving any radiation-associated CAD time to develop.
Overall, CAD was seen in 10.5% of patients who received left-sided radiation therapy and 5.9% of patients who received right-sided radiation therapy. No other factors examined made a significant impact on this trend.
“Our study adds to the growing evidence that left-sided radiation therapy is an independent risk factor for future heart disease after treatment for breast cancer,” co-author Gordon Watt, PhD, of Memorial Sloan Kettering Cancer Center in New York City, said in a prepared statement. “It is important that clinicians caring for younger breast cancer patients communicate the importance of radiation therapy for breast cancer while explaining the need for long-term attention to the risk of heart disease, particularly for women receiving left-sided radiation therapy.”
Of course, Watt emphasized, none of this means radiation should not considered for these patients.
“Radiation therapy is an indispensable part of breast cancer care, and the good news for breast cancer patients is that modern techniques and computerized treatment planning have reduced the amount of radiation that reaches the heart, thereby reducing the risk of developing heart disease,” he said.
One limitation of the team’s work was that patients self-reported CAD, and the researchers did not separately confirm every diagnosis. Also, as Watt indicated, updated techniques have reduced the amount of exposure associated with radiation therapy. These data may be heavily influenced by the fact that these updated methods were not around when many of the patients received their diagnosis and were treated.
The full study is available here.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.