In 1973, two researchers published an article in the journal Lab Investigation saying that radiation to the breast area might damage the capillaries and restrict blood flow to the heart.
Since that time, conflicting reports about the long-term risk of radiation to the heart have been published. According to a study released today in the International Journal of Radiation Oncology* Biology*Physics , the official journal of ASTRO, elderly women who receive radiation therapy for early-stage breast cancer appear to have no increased risk of a heart attack after taking pre-existing cardiac risk factors into account. Interestingly, pre-existing cardiac risk factors such as diabetes, hypertension and hyperlipidemia do not potentiate the effects of radiation on the heart.
Using the Surveillance, Epidemiology and End-Results (SEER) database, researchers conducted a retrospective study of female Medicare recipients aged 65 and older who were diagnosed with breast cancer from 1992 to 2000. Researchers then reviewed the records of more than 48,000 breast cancer patients. Of those women, 19,897 had lumpectomies (42 percent) and 26,534 has mastectomies (55 percent). Of all the patients in the study, 21,502 (45 percent) received radiation therapy and 4,151 (9 percent) received both radiation and chemotherapy. Patients with pre-existing heart disease were less likely to receive radiation.