People taking hormonal therapy medicine to treat breast or prostate cancer have a higher risk of heart attack and stroke as they get older and should be monitored regularly to detect any problems, according to a scientific statement by the American Heart Association.
The statement was published online on April 26, 2021, by the journal Circulation: Genomic and Precision Medicine. Read “Impact of Hormonal Therapies for Treatment of Hormone-Dependent Cancers (Breast and Prostate) on the Cardiovascular System: Effects and Modifications. A Scientific Statement From the American Heart Association.” (PDF)
About hormonal therapy
Hormonal therapy medicines treat hormone-receptor-positive breast cancers in two ways:
- by lowering the amount of estrogen in the body
- by blocking the action of estrogen on breast cancer cells
Estrogen makes hormone-receptor-positive breast cancers grow. So reducing the amount of estrogen or blocking its action can reduce the risk of early-stage hormone-receptor-positive breast cancers coming back (recurring) after surgery. Hormonal therapy medicines also can be used to help shrink or slow the growth of advanced-stage or metastatic hormone-receptor-positive breast cancers.
Hormonal therapy medicines are not effective against hormone-receptor-negative breast cancers.
There are several types of hormonal therapy medicines used to treat breast cancer:
- aromatase inhibitors: Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole)
- SERMs (selective estrogen receptor modulators): tamoxifen, Evista (chemical name: raloxifene), and Fareston (chemical name: toremifene)
- ERD (estrogen receptor downregulator): Faslodex (chemical name: fulvestrant)
In most cases, you take hormonal therapy for 5 to 10 years after surgery for hormone-receptor-positive breast cancer.
Hormonal therapy medicines can cause a range of side effects, including heart attack and stroke, known collectively as cardiovascular disease. But according to the American Heart Association, there has never been a comprehensive review of the data or recommendations from any professional society. So an expert team was created to review the scientific evidence and develop recommendations for use of hormonal therapy for treating people with breast or prostate cancer.
About the recommendations
The expert team’s main findings and recommendations are:
- People diagnosed with breast and prostate cancer who are treated with hormonal therapy have a higher risk of heart attack and/or stroke as they age.
- People who have two or more heart disease risk factors, such as high blood pressure, high cholesterol, obesity, smoking, or a family history of heart disease or stroke, have an even higher risk of cardiovascular problems when taking hormonal therapy.
- The longer a person takes hormonal therapy, the higher their risk of heart attack and stroke.
- Tamoxifen increases the risk of blood clots, while aromatase inhibitors increase the risk of heart attack and/or stroke.
- People taking hormonal therapy should be monitored for high blood pressure, blood clots, congestive heart failure, atherosclerosis (build-up of plaques on the walls of the arteries), and high cholesterol.
- People with two or more cardiovascular risk factors should have an annual echocardiogram, as well as imaging and/or blood tests to monitor heart health.
According to the statement, about 1.8 million people in the United States were diagnosed with cancer by the end of 2020, and 5% of them were considered to be at high risk for heart disease. As the population ages and cancer treatments improve, the number of cancer survivors is expected to increase from 16.9 million in 2019 to 22.1 million by 2030.
“With this increase in the number of cancer survivors and high prevalence of [cardiovascular disease] among patients with cancer and cancer survivors, clinicians must be highly effective in detecting and preventing adverse cardiovascular outcomes in this patient population,” the authors wrote.
The researchers also pointed out that detecting and effectively treating heart disease is particularly important for people who have been diagnosed with breast or prostate cancer because heart disease has become the leading cause of death among people treated for these two cancers.
“A team-based approach to patient care that includes the oncology team, cardiologist, primary care clinician, dietician, endocrinologist and other health care professionals as appropriate is needed to work with each patient to manage and reduce the increased risk of heart disease and strokes associated with hormonal therapy in breast and prostate cancer treatment,” Tochi Okwuosa, D.O., FAHA, chair of the scientific statement writing group, associate professor of medicine and cardiology, and director of Cardio-Oncology Services at Rush University Medical Center, said in a statement.
“For patients who have two or more cardiovascular risk factors, it is likely that referral to a cardiologist would be appropriate prior to beginning hormone treatment,” she added. “For patients already receiving hormonal therapies, a discussion with the oncology team can help to determine if a cardiology referral is recommended.”
What this means for you
If you’re taking hormonal therapy to treat breast cancer, it makes sense to talk to your doctor about these recommendations and ask how you are being monitored for heart disease, including blood clots and high blood pressure. If you have any concerns, it also makes sense to ask for a referral to a cardiologist.
If you have two or more risk factors for heart disease and will be starting hormonal therapy, it makes sense to ask your doctor for a referral to a cardiologist before you start hormonal therapy. The cardiologist can take baseline measurements of your heart health and set up a schedule for monitoring you while you’re taking hormonal therapy.
Together, you and your care team can set up a schedule to monitor your heart health and detect any issues early, when they are most treatable.
Written by: Jamie DePolo, senior editor
Reviewed by: Brian Wojciechowski, M.D., medical adviser
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