Newer Breast Cancer Meds Have Serious Cardiovascular Risks

Newer Breast Cancer Meds Have Serious Cardiovascular Risks

While the chemotherapy drug tamoxifen has long been associated with a risk of fatal cardiovascular events, a recent study shows that a newer class of breast cancer drugs has the same level of risk. However, aromatase inhibitors also have an increased risk of less severe cardiovascular complications compared to tamoxifen.

The three aromatase inhibitors on the market are anastrazole (Armidex), exemestane (Aromasin) and letrozole (Femara).

In older breast cancer survivors, cardiovascular disease is a leading cause of death. Prior research had already associated tamoxifen with an increased risk of fatal cardiovascular events, such as heart attack and stroke. But the new study is one of the first to demonstrate that aromatase inhibitors, though newer, have a similar risk profile in this area.

And it also found that women with breast cancer who had taken either aromatase inhibitors alone or after tamoxifen treatment had between a 26% and 29% higher risk of less serious cardiovascular events, such as irregular heart beat and swelling and irritation of a membrane surrounding the heart, compared to women who had only taken tamoxifen. The new research was published in JAMA Oncology.

“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,” Reina Haque, PhD, MPH, research scientist, Kaiser Permanente Southern California Department of Research & Evaluation, said in a statement.

“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,” she added.

Estrogen and progesterone are hormones produced by women that can promote the growth of some breast cancers. Aromatase inhibitors work by blocking the activity of an enzyme called aromatase, which the body uses to make estrogen in the ovaries and in other tissues. Tamoxifen binds to estrogen receptors and interferes with estrogen’s ability to stimulate the growth of breast cancer cells.

Clinical guidelines recommend tamoxifen for five years for women with breast cancer to cut the trisk of the cancer returning. Some postmenopausal women choose to only take aromatase inhibitors, while others choose to take tamoxifen for one to five years, followed by using aromatase inhibitors.

DISCLAIMER: MedShadow provides information and resources related to medications, their effects, and potential side effects. However, it is important to note that we are not a substitute for professional medical advice, diagnosis, or treatment. The content on our site is intended for educational and informational purposes only. Individuals dealing with medical conditions or symptoms should seek guidance from a licensed healthcare professional, such as a physician or pharmacist, who can provide personalized medical advice tailored to their specific circumstances.

While we strive to ensure the accuracy and reliability of the information presented on MedShadow, we cannot guarantee its completeness or suitability for any particular individual's medical needs. Therefore, we strongly encourage users to consult with qualified healthcare professionals regarding any health-related concerns or decisions. By accessing and using MedShadow, you acknowledge and agree that the information provided on the site is not a substitute for professional medical advice and that you should always consult with a qualified healthcare provider for any medical concerns.

Was This Article Helpful?

Show Comments (1)
0 0 votes
Article Rating
Notify of
1 Comment
Most Voted
Newest Oldest
Inline Feedbacks
View all comments
Lynn DiNardo

I have been on Femara for almost 10 years after 3 battles with breast cancer. What are the pros and cons of being on this long? My doctor is thinking of stopping it in August
thank you,


Would love your thoughts, please comment.x