All women have at least some risk for breast cancer. But some are more likely than others to eventually develop the disease. Health organizations — including the American Society of Clinical Oncology (ASCO) — urge that these high-risk women talk with their doctor about chemoprevention. Certain drugs may actually be able to help reduce the risk for breast cancer.
Chemoprevention uses drugs to lower a woman's risk for some breast cancers. It includes the medications tamoxifen and raloxifene. Doctors initially prescribed tamoxifen as a treatment for breast cancer. It helps prevent the disease from returning after surgery. Scientists originally developed raloxifene to treat osteoporosis, a disease that gradually weakens and thins bones.
Studies show that these drugs can reduce — but not eliminate — the risk for breast cancer by up to 50 percent. How? They belong to a larger group of drugs called selective estrogen response modifiers (SERMs). These work by reacting against the hormone estrogen. In some types of breast cancer, estrogen can stimulate cancer cells to grow in the breast tissue. SERMs can hinder this process.
The ASCO and the U.S. Preventive Services Task Force recently updated their guidelines on chemoprevention for healthy women. Both organizations now stress that women at high risk for breast cancer should talk with their doctor about the medication. Those at high risk include women with a family history of the disease or a past use of hormone therapy, among other factors.
Experts limit chemoprevention to high-risk women because of serious side effects. The drugs can cause hot flashes and night sweats. Much more concerning is their tendency to raise a woman's risk for cancer of the uterus. They can also cause deadly blood clots. Tamoxifen has been linked to cataracts, too.
The latest estimates show very few women eligible for chemoprevention are using it. The side effects may be one reason. Many women may also simply not know about the drugs. And those who do may not fully understand their benefit.
Should you consider chemoprevention? Talk with your doctor about your risk for breast cancer. This risk assessment can help with the conversation.
If you are interested talking about chemoprevention with your doctor but not sure where to start, try these questions:
What is my risk for breast cancer?
Should I consider chemoprevention?
Can I wait to start chemoprevention?
Which medicine — tamoxifen or raloxifene — is better for me? Why?
What side effects should I be most concerned about?
Is there anything I can do about side effects, such as hot flashes?
Are there other ways I can lower my risk for breast cancer?
American Cancer Society
Agency for Healthcare Research and Quality