The risk of the most serious cardiovascular events, including cardiac ischemia and stroke, was not higher for breast cancer survivors who received an aromatase inhibitor compared with tamoxifen users, a study published in JAMA Oncology has shown.1
Although cardiovascular disease is a significant cause of death in older patients with breast cancer, the long-term effect of aromatase inhibitor use on cardiovascular disease risk in breast cancer survivors remains unclear.
Therefore, researchers sought to determine the long-term impact of adjuvant endocrine therapies on cardiovascular disease risk among postmenopausal breast cancer survivors by accounting for major cardiovascular disease risk factors, medication use, chemotherapy, and radiotherapy.
For the retrospective study, researchers analyzed data from 13 273 postmenopausal women with hormone receptor (HR)-positive breast cancer diagnosed between 1991 and 2010, and followed up through 2011, from California. Patients had no prior history of cardiovascular disease.
Results showed that aromatase inhibitor users had a similar risk of cardiac ischemia (myocardial infarction and angina; HR, 0.97; 95% CI, 0.78-1.22) and stroke (HR, 0.97; 95% CI, 0.70-1.33) as tamoxifen users.
However, researchers found that women who received an aromatase inhibitor only or sequentially after tamoxifen and nonhormone users had an increased risk of other cardiovascular disease events, including dysrhythmia, valvular dysfunction, and pericarditis, compared with tamoxifen only users. The authors note that this finding necessitates further study.
1. Haque R, Shi J, Schottinger JE, et al. Cardiovascular disease after aromatase inhibitor use [published online ahead of print April 21, 2016]. JAMA Oncol. doi:10.1001/jamaoncol.2016.0429.