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Breast Cancer Prevention Drugs: What Women Should Know About Chemoprevention Agents

  • Approximately 1 in 8 women in the U.S. will develop breast cancer in their lifetime. But not every woman’s chances of developing the disease are the same, and those with more risk factors might benefit from taking chemoprevention agents.

    Chemoprevention agents are drugs that can inhibit or slow the growth of cancer cells. For some women who don’t currently have breast cancer, taking medications like tamoxifen, raloxifene, or aromatase inhibitors can help reduce their odds for getting some types of the disease in the future, according to new recommendations from the U.S. Preventive Services Task Force (USPSTF).

    Here’s some more information about these recommendations and how you and your doctor can decide whether these medications are right for you.

    Who benefits from chemoprevention agents?

    Medications like tamoxifen and raloxifene work by blocking the effects of estrogen in breast tissue, while aromatase inhibitors work by stopping other hormones in the body from turning into estrogen. Both of those mechanisms can help thwart the development of breast cancers that are estrogen receptor-positive (ER-positive).

    Women who are at high risk of developing breast cancer and at low risk for adverse side effects can benefit from taking chemoprevention drugs and, according to the USPSTF, they should be offered the option of taking them.

    You may be a candidate for the drugs if you have a combination of risk factors for breast cancer, including if you:

    • Are older
    • Have a family history of breast cancer, especially breast cancer at younger ages
    • Have had an abnormal breast biopsy result, such as atypical ductal hyperplasia, atypical lobular hyperplasia, or lobular carcinoma in situ
    • Have never been pregnant or had their first pregnancy at age 30 or later
    • Early onset of menarche (age 11 or younger)

    Together, you and your doctor can review your individual risk factors to determine whether your chances for developing breast cancer are higher than average. If they are, it makes sense to have a conversation about taking chemoprevention agents.

    Weighing the pros and cons

    If you are at increased risk for breast cancer, it doesn’t automatically mean chemoprevention medications are a good choice for you. Tamoxifen, raloxifene, and aromatase inhibitors all have the potential to cause significant side effects. These include:

    • For tamoxifen and raloxifene: blood clots and a higher risk of uterine cancer
    • For aromatase inhibitors: hot flashes, bone and muscle pain, and decreased bone density and a higher risk of fractures

    It’s vital to make a fully informed decision by talking with your doctor about the potential benefits and downsides of taking chemoprevention agents. For instance, if you’re already at risk for developing blood clots or certain other cancers, you’ll want to seriously consider how chemoprevention drugs might further raise your risk.

    Turn to the experts

    At Fox Chase Cancer Center, our multidisciplinary team of breast health experts can help you decide if you might benefit from taking chemoprevention drugs to reduce your risk of breast cancer. To make an appointment, call 888-FOX-CHASE.