Cardiac Morbidity and Mortality in Women with Ductal Carcinoma In Situ of the Breast Treated with Breast Conservation Therapy

Left-sided breast irradiation has been associated with increased risk of cardiac morbidity and mortality in some studies. This study examines the cardiac toxicity of irradiation in left- versus right-sided patients with ductal carcinoma in situ (DCIS). The medical records of 129 patients with DCIS treated with breast conservation therapy (BCT) at the Moffitt Cancer Center from 1986 to 2002 were reviewed and data regarding subsequent breast cancer and cardiac events were recorded. There were 59 left-sided and 70 right-sided patients treated. Mean age was 55 years. At 8 years, there was no significant difference observed between right- and left-sided breast cancer patients in the development of coronary artery disease, myocardial infarction, congestive heart failure, arrhythmia, valvular disease, cardiomyopathy, or cardiac-related death. Among those patients with left-sided breast cancer, 13.5% of patients developed a cardiovascular event compared to 7% of right-sided patients (p = 0.25). The overall survival at 8 years was 96% and the relapse-free survival was 85%. There were no significant differences in cardiac mortality or morbidity between right- and left-sided DCIS patients treated with BCT. Longer follow-up will be required to ascertain whether late events are more prevalent in left-sided patients.