Breast Cancer: Medications to Reduce Risk
Medications to Lower Breast Cancer Risk
This section covers the following topics:
Note that when we use the terms "female" and "women" we are referring to people assigned female at birth.
Can medications lower the risk for breast cancer?
Healthy, high-risk women may benefit from medications to lower their risk for breast cancer. This approach to lowering risk is sometimes called "." The two types of medications used to lower the risk for breast cancer in women block the hormone . Most of the research on these medications have studied women with increased risk for breast cancer due to a family history of cancer or certain breast changes found on biopsy. There has been very little research on how well these medications work in women with an linked to breast cancer risk and how much risk remains. For this reason, most experts advise high-risk women to continue screening while on .
Other drugs and vaccines are being tested in clinical trials to see if they may also lower the risk for breast cancer in high-risk women. See below for a list of some of the studies enrolling high-risk women.
High-risk women who wish to consider medications to lower their risk for breast cancer should discuss the benefits, risks and limitations with their health care provider.
SERMs (Selective Receptor Modulators)
The two SERMs most commonly used to lower breast cancer risk are tamoxifen and raloxifene.
- Tamoxifen is a drug that is used both to treat and prevent breast cancer. It blocks the effect of on breast tissue. Tamoxifen is approved for use in both pre- and post-menopausal women. When taken for five years, it reduces breast cancer risk by up to 40%; this protective effect continues beyond the five-year treatment period. Tamoxifen may also protect bone density and reduce risk in postmenopausal women who cannot take hormone replacement therapy. Side effects of tamoxifen may include hot flashes, an increased risk of endometrial cancer and blood clots. Research has shown that a low dose of tamoxifen may offer similar protection while lowering the risk for side effects. Some experts refer to this low dose as "Baby Tam."
- Raloxifene works in a similar way as tamoxifen. It is used to lower breast cancer risk in postmenopausal women. Raloxifene has a lower risk for endometrial cancer and blood clots and fewer side effects than tamoxifen. The most common side effects are hot flashes, blood clots, nausea and weight gain.
Aromatase inhibitors
Aromatase inhibitors are medications that block production of in postmenopausal women. Common aromatase inhibitors include anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin).
Unlike SERMs, aromatase inhibitors do not improve bone density. In fact, they may actually accelerate bone loss in postmenopausal women. However, aromatase inhibitors tend to cause fewer side effects and do not appear to have the risk of blood clots or endometrial cancer seen with tamoxifen.
Paying for medications to reduce risk
The federal Affordable Care Act requires most health insurance companies to pay for medications to lower the risk for breast cancer in high-risk women 35 and older with no out-of-pocket costs.
Despite federal and , some health plans still deny coverage for high-risk screening or charge large out-of-pocket fees. You can file an appeal with your health plan. Visit our page with tips for filing an appeal.
Vaccines and other medications in research
Researchers are testing other drugs and vaccines to see if they can lower breast cancer risk in high-risk people.
- The drug denosumab is used to increase bone strength in people with (bone weakening) or people with cancer who are at risk for bone weakening. A study known as BRCA-P is looking at whether this drug could lower the risk for breast cancer in high-risk women.
- PARP inhibitors are targeted therapies used to treat cancer in people with or mutations. Researchers are looking at designing studies using PARP inhibitors to lower the risk for cancer in people with these mutations.
- Several different vaccines are being tested in clinical trials enrolling people with inherited mutations.
Participate in prevention research
Testing a Vaccine for Cancer Prevention in People with a BRCA1 or BRCA2 Mutation
Clinicaltrials.gov identifier:
NCT04367675
Testing a Vaccine for Preventing or Treating Triple-Negative Breast Cancer
Clinicaltrials.gov identifier:
NCT04674306
Find Experts
The following resources can help you locate an expert near you.
Finding breast experts
- The National Accreditation Program for Breast Centers has two search tools:
- find an accredited breast center
- find a breast surgeon
Related experts
Finding a plastic surgeon
- The American Society of Plastic Surgeons has a searchable Plastic Surgeon Referral Service database.
Other ways to find experts
- Register for the FORCE Message Boards and post on the Find a Specialist board to connect with other people who share your situation.
- The National Cancer Institute (NCI)-Designated Comprehensive Cancer Centers have specialists to manage the symptoms and side effects of cancer prevention or treatment.