Does Radiotherapy for Breast Cancer Increase Risk of Heart Disease?

I was leafing through the latest edition of The New England Journal of Medicine when I came across new research, reporting the correlation between the radiation dose that women receive during breast cancer treatment and a higher risk of developing heart disease in later life.

What is Radiotherapy?

Radiotherapy is a popular treatment for early stage breast cancer. It is effective in preventing the relapse of disease as well as morbidity. When radiotherapy treatment was originally developed women were exposed to much higher doses of radiation. However, due to developments in technology, today, women can receive effective radiotherapy treatment at a lower dose. External beam radiology is more exact, targeting the cancerous tissue effectively, without damaging surrounding healthy tissue and organs.

Today women are typically exposed to between 1-5Gy of radiation during their breast cancer treatment, and according to experts, these doses of radiation can cause the development of heart disease. However, despite the advances in medicine, it still remains unknown exactly what is the magnitude of the risk to: women’s hearts, the degree of influence on pre-existing cardiac factors, and the time frame in which the development of the heart disease occurs post-radiation therapy.

The researchers in the New England Journal of Medicine study set out to investigate how the factors listed above contribute to the development of cardiac disease post radiotherapy for breast cancer.


Study Results

After studying a group of 2,168 women under the age of 75 in Sweden and Denmark, which received radiation therapy for breast cancer between the years 1958-2001, the researchers found that in general, a women’s risk for a cardiac event increased 7.4%. per increase of gray of radiation (this is the unit radiation dose is measured, women receive between 1-5).

Which breast treated also holds importance. Women, who received radiation to the left breast, had a higher risk of developing a cardiac event. This may occur because of the left breast’s proximity to the heart. There is more danger of the heart receiving a higher dose of radiation, as it is closer to the left breast than the right.

The presence of pre-existing heart conditions, as well as circulatory conditions also had a role to play. Women had increased risk of developing heart disease if they had of history of past cardiac events, as well as a history of diabetes, high BMI, COPD and if they smoked.

As with any medical treatment there is always the risk of developing side effects (Cardiology Associates Panama City). Dr. Hope Rugo, a professor of medicine in San Francisco suggested that the results should be interpreted with caution.

Radiotherapy for breast cancer is considered a lifesaving treatment. The results of this study, if interpreted incorrectly, could deter women from receiving treatment. Dr. Hope Rugo noted that the results showing an increase in the development of a cardiac event, were from women who received radiation therapy in the 1980’s. At this time, radiation doses were significantly higher.

Robyn Nazar

As a registered nurse and health writer, Robyn Nazar is committed to empowering patients with knowledge about their health and the choices available to them. With her clinical background in women's health, obstetrics, neonatal care, cardiology and general practice, Robyn strives to connect with readers on a wide variety of health topics. Today, Robyn's online following has grown into a large community of patients and health professionals who regularly engage with her on the web. In addition to her own blog:The Health Update Robyn also contributes to health blog Modern Health. Robyn lives with her husband and their new baby girl.

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