Adjuvant radiotherapy for breast cancer and cardiac morbidity

 

Adjuvant radiation for breast cancer has been shown to increase the risk of cardiac mortality, particularly for those women with left-sided breast cancers.  However, recent data suggest that this risk of cardiac toxicity is declining.  We evaluated cardiac morbidity, which may be an earlier and more sensitive indicator of cardiac damage to determine the risk among patients treated in more recent years. 

We compared women with left and right-sided breast cancer who received adjuvant radiation, because women with left-sided breast cancer have more cardiac exposure to radiation but otherwise are indistinguishable from those women with right-sided breast cancer.  With a mean follow-up of 9.5 years, our study found no difference in the rates of hospitalizations for ischemic heart disease (including myocardial infarction), valvular heart disease, conduction abnormalities, or heart failure between those women with left and right-sided breast cancers. 

These data are reassuring that patients receiving radiation using modern techniques are not experiencing significant toxicities.  However, we caution that toxicity from radiation is a late side-effect and further follow-up is warranted to determine if differences will emerge. 

 

Reference:

Patt DA et al.: "Cardiac morbidity of adjuvant radiotherapy for breast cancer", J Clin Oncol. 2005 Oct 20;23(30):7475-82. Epub 2005 Sep 12

 

Sharon Giordano

Department of Breast Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX