How radiotherapy protects the hearts of breast cancer patients
Women with breast cancer face an elevated risk of developing cardiovascular disease or suffering a myocardial infarction. According to new data published in European Heart Journal, however, radiotherapy can help combat those risks and significantly improve a woman’s long-term heart health.[1]
Researchers examined data from more than 100 breast cancer patients who underwent radiotherapy treatment without chemotherapy and presented with no prior history of cancer treatment. The mean patient age at the time of treatment was 58 years old.
Study participants underwent coronary CT angiography (CCTA) imaging prior to radiotherapy treatment and two years following radiotherapy. Coronary inflammation was measured in each coronary artery using perivascular fat attenuation index (FAI) scores. Long-term mortality risks were calculated using a AI-risk prognostic model, which uses both FAI scores and a variety of clinical risk factors. FAI scores and long-term mortality risks were also calculated prior to radiotherapy and two years following radiotherapy.
All patients had “significantly elevated inflammation” in their coronaries at the time of treatment. Mean FAI scores were 87.05 for the right coronary artery, 77.96 for the left anterior descending artery and 79.82 for the left circumflex artery. Two years following radiotherapy, coronary calcification had increased in these patients, but inflammation as measured by FAI scores had significant fallen in each of the coronaries.
The study’s authors emphasized that radiotherapy appeared to substantially reduce the group’s long-term risk of cardiac mortality. In fact, the mean eight-year predicted risk for cardiac mortality, as measured by the AI-risk prognostic model, dropped from 10.41% before radiotherapy to 8.92% two years after radiotherapy.
These changes did not seem to be related to radiation exposure, the group note. It was much more likely that the changes were the result of radiotherapy attacking the tumors inside these patients and reversing the damage they were doing.
“Women with breast cancer are at high risk for heart attacks because the tumor triggers severe inflammation in the heart arteries,” corresponding author Charalambos Antoniades, MD, PhD, chair of cardiovascular medicine at the University of Oxford, told Cardiovascular Business. “Radiotherapy reverses these detrimental effects of the tumor on the heart, reducing the eight-year risk for cardiac mortality by ~15% despite the increase in coronary artery calcium.”
Antoniades added that the radiation levels associated with radiotherapy for breast cancer patients is much lower now than it once was due to years and years of hard work to minimize radiation doses and improve treatment techniques.
“High radiation doses have been proposed to harm the coronary arteries and increase the risk of heart attacks statistically,” he said. “That was believed to be because of direct damage of the heart arteries by the X-rays passing through them. However, the low radiation doses used today do not appear to have these direct detrimental effects on the heart. By treating the tumor, radiotherapy actually protects the heart!”
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Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.