Aromasin (chemical name: exemestane) is an aromatase inhibitor approved by the U.S. Food and Drug Administration (FDA) to treat:
- postmenopausal women diagnosed with hormone-receptor-positive, early-stage breast cancer after they've taken tamoxifen for 2 to 3 years to reduce the risk of the cancer coming back
- postmenopausal women diagnosed with advanced-stage or metastatic hormone-receptor-positive breast cancer
Women stop taking tamoxifen when they start taking Aromasin.
Aromatase inhibitors can't stop the ovaries from making estrogen, so aromatase inhibitors are mainly used to treat postmenopausal women. But because aromatase inhibitors are so much more effective than tamoxifen in postmenopausal women, researchers wondered if there were a way to successfully treat premenopausal women diagnosed with hormone-receptor-positive, early-stage breast cancer with an aromatase inhibitor. Results from the SOFT (Suppression of Ovarian Function Trial) study published in 2015 suggest that premenopausal women diagnosed with hormone-receptor-positive breast cancer can be successfully treated with Aromasin if their ovarian function is suppressed. If you’re a premenopausal woman willing to take medicine to suppress your ovaries, you may be able to take Aromasin instead of tamoxifen for your hormonal therapy treatment.
Aromasin won't work on hormone-receptor-negative breast cancer.
Aromasin is a pill taken once a day. Most doctors recommend taking Aromasin at the same time each day.
You should not take Aromasin if you are breastfeeding, pregnant, trying to get pregnant, or if there is any chance that you could be pregnant. Aromasin may cause damage to developing embryos. You should use an effective non-hormonal type of birth control — such as condoms, a diaphragm along with spermicide, or a non-hormonal I.U.D. — while you are taking Aromasin. Ask your doctor which type of non-hormonal birth control would be best for you, as well as how long you should use this type of birth control after you stop taking Aromasin.
Benefits of Aromasin
The large IES (Intergroup Exemestane Study) trial was started in 1998 and compared switching to Aromasin after taking tamoxifen for 2 to 3 years to staying on tamoxifen for 5 years. The results have shown that switching to Aromasin for 2 to 3 years AFTER taking tamoxifen 2 to 3 years (for a total of 5 years of hormonal therapy medicine) was better than staying on tamoxifen for 5 years for:
- increasing the time before the cancer comes back in those who experience a recurrence
- reducing the risk of a new cancer developing in the other breast
for postmenopausal women diagnosed with hormone-receptor-positive, early-stage breast cancer.
Research published in 2011 showed that Aromasin can lower risk in high-risk, postmenopausal women who've never been diagnosed with breast cancer. Aromasin is not approved by the FDA for this use, but doctors may consider it a good alternative to tamoxifen or Evista. In 2013, the American Society of Clinical Oncology (ASCO) released new guidelines on using hormonal therapy medicines to reduce breast cancer risk in high-risk women. These guidelines recommend that doctors talk to high-risk postmenopausal women about using Aromasin to reduce risk. ASCO is a national organization of oncologists and other cancer care providers. ASCO guidelines give doctors recommendations for treatments that are supported by much credible research and experience.
It's possible that the FDA may approve Aromasin to be used to reduce risk in high-risk, postmenopausal women who haven’t been diagnosed.
Side effects of Aromasin
Because Aromasin lowers the amount of estrogen in the body, less estrogen reaches bone cells, which can lead to bone thinning and weakening and a higher-than-average risk of broken bones. This side effect can be very troubling for some women. If you have osteoporosis, your doctor may recommend that you take tamoxifen rather than Aromasin because of this possible side effect.
Other common side effects of Aromasin are:
Some women may have other side effects while taking Aromasin:
How long do I take Aromasin?
In most cases, you'll take Aromasin for 2 or 3 years. Doctors may recommend that some women take it for a longer time.
Does insurance cover Aromasin?
While costs vary, Aromasin can cost several hundred dollars per month. Aromasin also is available as a generic medicine, which is usually less expensive. If you have health insurance, check with your insurance company to see if and how much of the cost of Aromasin is covered. If you don't have health insurance or your insurance doesn't cover the cost of Aromasin, ask your doctor or nurse about programs in your area that may be able to help.
Pfizer, the company that makes Aromasin, offers the First RESOURCE and the Pfizer Pfriends programs that may be able to help cover the cost of Aromasin. The phone numbers are:
- Pfizer Oncology Together: 1-877-744-5675
- Pfizer RxPathways: 1-866-706-2400
You can also visit the Aromasin website for more information.
You can also read the Breastcancer.org Paying for Your Care section for information on additional types of financial assistance and cost-lowering tips.