Aromatase Inhibitors DrugBank Online
Aromatase inhibitors are a class of drug used to prevent cancer recurrence in postmenopausal women with estrogen receptor-positive breast cancer. These medications also are prescribed for premenopausal women in combination with ovarian suppression therapy and for men with breast cancer who are unable to take tamoxifen. In large studies, both anastrozole and exemestane have been shown to lower breast cancer risk in postmenopausal women who are at increased risk 17, 18, 19, 20, 21. For example, they might be a reasonable option for women who have an increased risk of blood clots and therefore should not take tamoxifen or raloxifene 22. Aromatase inhibitors block this pathway and consequently suppress estrogen levels in postmenopausal women.
Long-term follow-up of another randomized trial, the International Breast Cancer Intervention Study I, found that 5 years of tamoxifen treatment reduces the incidence of breast cancer for at least 20 years (26). A subsequent large randomized trial, the Study of Tamoxifen and Raloxifene, which was also sponsored by NCI, found that 5 years of raloxifene(a SERM) reduces breast cancer risk in such women by about 38% (27). Hormone therapy for breast cancer is a treatment for breast cancers that are sensitive to hormones. Some forms of hormone therapy for breast cancer work by blocking hormones from attaching to receptors on cancer cells. Other forms work by decreasing the body’s production of hormones. A 2015 study found that combining aromatase inhibitors with ovarian suppression medications was effective in reducing the risk of cancer recurrence in premenopausal women with breast cancer.
Aromatase inhibitors should not be used in people with a known hypersensitivity to any of the active or inactive ingredients in the drug. With that being said, a drug allergy is not common with aromatase inhibitors, affecting less than one out of 10,000 users. Unlike tamoxifen and raloxifene, AIs tend to speed up bone thinning, which can lead to osteoporosis. Find a list of questions on hormone therapy you may want to ask your health care provider. However, some premenopausal women may take an aromatase inhibitor when combined with ovarian suppression.
Completing aromatase inhibitor therapy
Aromatase inhibitors work by binding to aromatase and preventing aromatization from occurring. By doing so, the production of estrogen may be reduced by as much as 95% in postmenopausal women. Despite these benefits, aromatase inhibitors can cause significant side effects, including accelerated bone loss leading to osteoporosis. When used to lower breast cancer risk, these drugs are typically taken for 5 years.
- This side effect can be serious enough to cause some women to stop taking the drugs.
- Depending on your circumstances, you may undergo tests to monitor your medical situation.
- Furthermore, 8.1% of patients receiving erdafitinib experienced TRAEs leading to discontinuation, versus 13.4% of those on chemotherapy.
- Aromatase inhibitors are typically used to treat people who have already experienced menopause.
- Clinical trials have shown that two aromatase inhibitors – anastrozole and exemestane – can lower breast cancer risk in women who have never been diagnosed with the disease.
Hormone Therapy and Risk of Breast Cancer Recurrence
Until recently, most women who received adjuvant hormone therapy to reduce the chance of a breast cancer recurrence took tamoxifen every day for 5 years. Hormone therapy following surgery, radiation or chemotherapy has been shown to reduce the risk of breast cancer recurrence in people with early-stage hormone-sensitive breast cancers. It also can effectively reduce the risk of metastatic breast cancer growth and progression in people with hormone-sensitive cancers. People with estrogen-positive breast cancers may benefit from hormone therapy to prevent cancer from returning.
Breast cancers that lack estrogen receptors are called ER negative, and if they lack both estrogen receptor (ER) and progesterone receptor (PR) they may be called hormone receptor negative (HR negative). Approximately 67%–80% of breast cancers in women are ER positive (1, 2). Approximately 90% of breast cancers in men are ER positive and approximately 80% are PR positive (3). Dianabol Elbrus Pharmaceuticals buy pharmacy Aromasin (exemestane) is a member of the aromatase inhibitors drug class and is commonly used for Breast Cancer. One goal of aromatase inhibitor treatment is to lower estrogen levels. Many women are prescribed hormone therapy for five to 10 years, so the cost can be an important consideration.
Learn about the importance of completing treatment with an aromatase inhibitor. Anastrozole, exemestane and letrozole are equally effective and have similar side effects [90, ]. To learn about a specific aromatase inhibitor, visit the National Institutes of Health’s Medline Plus website.
Quoted prices are for cash-paying customers and are not valid with insurance plans. This price guide is based on using the Drugs.com discount card which is accepted at most U.S. pharmacies. Explore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions.