Aromatase inhibitor (AI) therapy is associated with endothelial dysfunction, a predictor of cardiovascular disease, among postmenopausal women with breast cancer, according to findings presented at the 2016 San Antonio Breast Cancer Symposium.1

Impaired endothelial function is associated with acute coronary syndrome, chest pain, myocardial infarction, and cardiac death.

Impaired endothelial function in study participants was “independent of the duration of AI use,” said lead study author Anne H. Blaes, MD, associate professor of hematology and oncology at the University of Minnesota in Minneapolis.

“With a growing number of cancer survivors, it is very important that we look to understand the long-term complications from cancer treatment,” she said. “Most women with early-stage breast cancer are at greater risk of dying from cardiovascular disease than their breast cancer.”

Cardiovascular risk of AIs “has always been a concern,” Dr Blaes said. Additional research is needed to confirm the findings.

Adjuvant AI therapy reduces breast cancer mortality among women who have had surgery for estrogen receptor (ER)-positive disease, Dr Blaes noted. Because these patients tend to have long survival times, better understanding of the potential late complications of treatment is “imperative,” so that risks and benefits can be carefully examined, she said.

But clinical trial experience suggests that up to 17% of women taking adjuvant AIs might experience cardiac events.

The research team enrolled 36 postmenopausal women on AI therapy for locally-advanced breast cancer and 36 healthy postmenopausal control participants. Inclusion criteria included no history of tobacco use, hypertension or hyperlipidemia.

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Women administered AIs had elevated systolic blood pressure compared to controls (128 mmHg vs 114.5 mmHg) and elevated levels of d-dimer, an inflammation biomarker, Dr Blaes said. When large- and small-artery elasticity were evaluated, the EndoPAT ratio—a measure of endothelial function—was 0.8 in women administered AIs versus 2.7 among women in the control group.

Reference

  1. Blaes AH, Beckwith H, Hebbel R, et al. Aromatase inhibitors and endothelial function: is there an association with early cardiovascular disease? Paper presented at: 39th San Antonio Breast Cancer Symposium; Dec 2016; San Antonio, TX.