Breast Irradiation and Cardiac Toxicity

Breast irradiation is a critical element in breast conservation therapy for both early-stage invasive and noninvasive breast cancer (ductal carcinoma in situ). Large clinical trials have clearly and consistently demonstrated that breast irradiation reduces local disease recurrence, but it can also increase the risk for cardiac events, particularly for patients receiving left-sided irradiation.

To define this risk, investigators conducted a population-based, case-control study of major coronary events (defined as myocardial infarction, coronary revascularization, or death from ischemic heart disease) in women who received external-beam radiotherapy for invasive breast cancer in Sweden and Denmark between 1958 and 2001. The study included 963 …