SOURCE: Kaiser Permanente, news release, April 21, 2016
THURSDAY, April 21, 2016 (HealthDay News) -- Treatment with estrogen-lowering drugs called aromatase inhibitors doesn't raise the risk of heart attacks and strokes among breast cancer survivors, a new study suggests.
However, the researchers did find that women who took the drugs had a slightly higher risk of less serious heart problems, such as an abnormal heart beat or swelling and irritation of the membrane surrounding the heart.
"Our study is a comprehensive assessment of the impact aromatase inhibitors have on cardiovascular risk and provides reassurance that the hormone therapy to reduce breast cancer recurrence does not increase risk of the most fatal cardiovascular events," said study author Reina Haque. She is a research scientist at Kaiser Permanente's Southern California Department of Research and Evaluation.
"A particular strength of our study is that we accounted for women's other potential cardiovascular risk factors, as well as medication used to treat high blood pressure and high cholesterol," Haque added in a Kaiser news release.
The study was published April 21 in the journal JAMA Oncology.
Cardiovascular disease is a leading cause of death in older breast cancer survivors, the study authors said. Previous research has linked tamoxifen, another commonly prescribed hormone-altering drug, with a serious risk of stroke, they added.
The new study included more than 13,000 postmenopausal women. The women were diagnosed with either progesterone or estrogen receptor-positive breast cancer. That means the growth of the breast cancer is fueled by one of those hormones.
The cancers were diagnosed between 1991 and 2010. The women's health was followed through 2011.
As part of their breast cancer treatment plan, some postmenopausal women take only aromatase inhibitors. In other cases, women may take tamoxifen for one to five years and then begin using aromatase inhibitors, the researchers explained.
In this study, more than 28 percent of the women took aromatase inhibitors. Almost 32 percent took tamoxifen. About 20 percent took both drugs. Just over 19 percent didn't take either drug, the researchers said.
The study found that women who took aromatase inhibitors didn't have a higher risk for heart attacks and stroke than those who took tamoxifen did.
But, women who took only aromatase inhibitors or used them after tamoxifen treatment had up to a 29 percent higher risk of less serious heart problems than those who took only tamoxifen, the research revealed.
The American Cancer Society has more about aromatase inhibitors.