Left Breast Radiation May Increase Heart Disease Risk in Breast Cancer Survivors
Radiation therapy is a cancer treatment that uses high energy x-rays to kill cancer cells and shrink tumors. It is often used after breast cancer surgery to reduce the risk of the cancer coming back.
Radiation therapy is routinely recommended for most patients after a lumpectomy. It is sometimes also recommended after a mastectomy depending on the stage of disease and other factors.
Possible Side Effects of Radiation
Radiation therapy is a very effective and widely used treatment for breast cancer. It is very well tolerated by most patients, but as with any treatment, it can have side effects.
Short-term potential side effects which usually resolve within two weeks of completing treatment include:
- Swelling to the breast
- Skin changes to the treated area, eg sunburn, redness, flaking, color changes
- Fatigue
- Pain to the treated area
- Hair loss to the treated area
- Sore throat (if the supraclavicular lymph nodes are treated)
Radiation therapy can also have long-term side effects:
- Breast and skin changes such as discoloration, firmness or shrinkage of the breast
- Can increase the risk of complications after breast reconstruction, especially implant-based reconstruction
- Lymphedema – if lymph nodes under the arm are treated, fluid may collect in the arm causing it to swell
Very rare long-term side effects can include:
- Rib fracture
- Lung inflammation or fibrosis
- Heart problems
- Increased risk of a second cancer (eg angiosarcoma)
Coronary Artery Disease
A recent study specifically evaluated the risk of heart problems in breast cancer survivors who had undergone radiation therapy. The study analyzed 972 women under the age of 55 when diagnosed with stage I or II invasive breast cancer between 1985 and 2008. The study found that women who had radiation therapy to their left breast, the same side of the body as their heart, had twice the risk of coronary artery disease (10.5%) compared to those who had radiation to their right breast (5.8%).
Coronary artery disease leads to decreased blood flow to the heart muscle. This can lead to chest pain (angina), shortness of breath, an abnormal heartbeat, heart failure, and even a heart attack (myocardial infarction).
“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”, said study co-author, Dr Gordon Watt. “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. 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.”
There have certainly been several major advances in the technology and techniques used to administer radiation therapy since the beginning of this study. There are also ways to avoid radiating parts of the chest that don’t need it, like body positioning and breath holding. These techniques and maneuvers weren’t used in the 1980’s. When combining all the advances, the dose of radiation delivered to the heart today is significantly less than during the early years of this study.
Despite the advances, if you are a patient with a left-sided breast cancer, we still strongly recommend you ask your radiation oncologist what techniques they’re using to protect your heart. This will ensure you are decreasing your risk of heart disease as much as possible.
