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Cardiac morbidity and mortality after breast conservation treatment in patients with early-stage breast cancer and preexisting cardiac disease.

BACKGROUND
This study was undertaken to determine the risk of late cardiac morbidity and mortality in patients with preexisting cardiac disease treated with contemporary radiation techniques for early-stage breast cancer.


PATIENTS AND METHODS
Medical records were reviewed for 41 patients with early-stage breast cancer and a history of myocardial infarction, congestive heart failure (CHF), and/or coronary artery disease before radiation therapy. Data were recorded on baseline cardiac disease and tumor characteristics, cardiac morbidity during and after treatment, and survival status of each patient. Patients were stratified for right- versus left-sided breast cancer and compared.


RESULTS
There was no significant difference in overall survival (OS) between the right- and left-sided groups (log-rank test; P = .19). The left-sided group had a higher incidence of cardiac deaths (right side, 2 of 26 [9%]; left side, 4 of 15 [27%]; hazard ratio, 4.2; P = .08) 10 years after treatment, including deaths secondary to myocardial infarction, CHF, or coronary artery disease. On the other hand, the right-sided group had a higher proportion of deaths secondary to breast cancer (right, 8 of 26 [31%]; left, 2 of 15 [13%]) and non-breast cancer/noncardiac causes (right, 7 of 26 [27%]; left, 1 of 15 [7%]).


CONCLUSION
Although OS was similar in both groups, radiation was associated with a higher incidence of cardiac death in patients with left-sided breast cancer. Efforts should be made to minimize cardiac exposure and also to promote more vigilant risk factor modification in this group of women.