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Breast Cancer Radiation Therapy Does Not Increase Risk of Heart Attack (dateline August 20, 2002)

A new study finds that treating breast cancer patients with radiation therapy does not increase the risk of heart attack. Some previous analyses have found a link between radiation therapy and heart attack, but the researchers of this latest study say those results are likely incorrect. Radiation is commonly used on breast cancer patients after breast-conserving therapy (lumpectomy) to help destroy any remaining cancer cells and prevent the cancer from recurring. The researchers say that while older versions of breast cancer radiation therapy may have been damaging, the treatments used today are not harmful.

To conduct the study, Katherine A. Vallis, MD, PhD, of the Princess Margaret Hospital/University Health Network in Toronto, and her colleagues analyzed records of 2,128 women who had undergone lumpectomy and radiation at Princess Margaret Hospital between 1982 and 1988. They studied the number of women who had died or been admitted to the hospital for heart attacks and compared them to the general population.

Previous studies have suggested that radiation therapy to the left breast in particular can narrow the arteries and increase the risk of a heart attack. However, after an average of 10.2 years follow-up, Dr. Vallis and her colleagues concluded that modern radiation therapy after breast cancer surgery is safe and does not contribute to an increased risk of heart attack.

While the link between heart attack and breast cancer radiation therapy has never been clearly established, Dr. Vallis and her colleagues believe that some previous studies that found an association were likely flawed because they may not have included information on how the radiation therapy was given or accounted for other medical factors that may have increased the women's risk for heart attack.

Another possibility is that previous studies may have included radiation techniques that were not modern or that the radiation was not administered correctly. According to Dr. Vallis and her colleagues, modern radiation therapy does not increase heart-related problems, though radiation technologists must still be attentive when treating the breast and chest wall.

Though Dr. Vallis and her team followed the women in their study for an average of 10 years, they plan to continue their follow-up to ensure that the risk of heart attack does not exist at any point after undergoing radiation therapy for breast cancer.

While the long-term risks of radiation therapy after breast cancer surgery appear to be negligible, the treatment does carry short-term risks:

  • Fatigue
  • Neutropenia (reduction in white blood cells)
  • Breast swelling or tenderness
  • Feeling of heaviness in the breast
  • Sunburn-like appearance of the breast skin
  • Loss of appetite

In the vast majority of cases, the benefits of treating breast cancer and preventing a recurrence of the disease with radiation therapy outweigh the risk of side effects or complications.

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