Adjuvant Radiation Therapy for Breast Cancer Affects Coronary Arteries

Although radiation therapy (RT) for early-stage breast cancer lowers risk for local recurrence and improves overall survival, this treatment has been associated with higher non–breast cancer–related mortality, primarily because of cardiac events. Data linking RT to cardiac events are largely inferential, without any clear demonstration of specific pathologic effects of RT on the heart. For example, compared with right-sided breast cancers, left-sided cancers have been associated with higher mortality from ischemic heart disease.

Now, Swedish investigators have conducted a cohort study of 199 women with breast cancer diagnosed from 1970 to 2003 who underwent coronary angiography from 1990 to 2004. Coronary artery stenosis was graded from 0 (n…