New evidence from an international collaboration indicates that extended estrogen suppression in postmenopausal breast cancer patients does not increase the risk of coronary artery calcification. This finding addresses a key concern regarding the balance between the benefits of estrogen suppression and potential cardiovascular risks in this population.
Aromatase inhibitors are a crucial component in treating hormone receptor-positive postmenopausal breast cancer. Given that coronary artery calcification is a significant predictor of heart disease, balancing the benefits of estrogen suppression with potential heart disease risks has been a critical issue.
The study, published in the Canadian Journal of Cardiology, was led by Yu Hiasa, MD, from Ehime University Graduate School of Medicine in Japan. It is a retrospective, cross-sectional observational analysis that examined the relationship between the duration of aromatase inhibitor treatment and the severity of coronary artery calcification in postoperative breast cancer patients. The study included 357 postmenopausal breast cancer patients who started adjuvant endocrine therapy with aromatase inhibitors.
Impact on Cardiovascular Health
Coronary artery calcification is believed to be associated with atherosclerosis, which can lead to angina and heart attacks. Estrogen plays a beneficial role in cardiovascular health, but its suppression is often necessary in breast cancer treatment. Hormonal therapy, particularly aromatase inhibitors that block estrogen production, is a standard post-surgery treatment for postmenopausal women with breast cancer. While these therapies effectively reduce cancer recurrence, concerns have grown about their potential cardiovascular side effects, including the acceleration of coronary artery atherosclerosis.
Hiasa stated, "Although there is an ongoing discussion on the optimal duration of aromatase inhibitor therapy (5 years or 10 years), our data suggest that longer aromatase inhibitor use (as often used to prevent or suppress late recurrences or spread of breast cancer) is safe, at least in regard to coronary artery calcification."
Key Findings
Coronary artery calcification was quantified using a visual ordinal scoring system, and patient characteristics were assessed based on the presence of coronary artery calcification. Independent risk factors for elevated coronary artery calcification scores were identified through a multivariable logistic regression model.
Co-investigator Akinori Higaki, MD, PhD, also from Ehime University Graduate School of Medicine, noted, "Our analysis of the postoperative breast cancer patient cohort revealed that the duration of treatment with aromatase inhibitors and the presence of osteoporosis were not associated with coronary artery calcification."
Novel Risk Factor Identified
In addition to well-known risk factors for coronary artery calcification, such as older age, hypertension, and diabetes mellitus, the researchers found that lower hemoglobin levels are also an independent risk factor for coronary artery calcification. In an accompanying editorial, Ibrahim Alfaris from Stanford University School of Medicine suggested that identifying low hemoglobin as a significant risk factor could lead to anemia being considered as an indication for cardiovascular screening in postmenopausal women undergoing aromatase inhibitor therapy.
