Family History

Women with close relatives who've been diagnosed with breast cancer have a higher risk of developing the disease.

If you've had one first-degree female relative (sister, mother, daughter) diagnosed with breast cancer, your risk is doubled. If two first-degree relatives have been diagnosed, your risk is 5 times higher than average.

If your brother or father have been diagnosed with breast cancer, your risk is higher, though researchers aren't sure how much higher.

In some cases, a strong family history of breast cancer is linked to having an abnormal gene associated with a high risk of breast cancer, such as the BRCA1 or BRCA2 gene. In other cases, an abnormal CHEK2 gene may play a role in developing breast cancer.

Steps you can take

There are lifestyle choices you can make to keep your risk of developing breast cancer as low it can be:

• maintaining a healthy weight
• exercising regularly
• limiting alcohol
• eating nutritious food
• never smoking (or quitting if you do smoke)

These are just a few steps you can take. Review the links on the left side of this page for more options.

Along with these lifestyle choices, there other risk-reduction options for women with a strong family history of breast cancer.

Hormonal therapy medicines: SERMs (selective estrogen receptor modulators) have been shown to reduce the risk of developing hormone-receptor-positive breast cancer in women at high risk. Tamoxifen and Evista (chemical name: raloxifene) are the two SERMs used in this way.

• Tamoxifen has been shown to reduce the risk of first-time hormone-receptor-positive breast cancer in both postmenopausal and premenopausal women at high risk. Certain medicines may interfere with tamoxifen's protective effects. Visit the tamoxifen page to learn more.
• Evista has been shown to reduce the risk of first-time hormone-receptor-positive breast cancer in postmenopausal women. Visit the Evista page to learn more.

Hormonal therapy medicines do not reduce the risk of hormone-receptor-negative breast cancer.

Together, you and your doctor can decide if medicine to lower your risk is a good option for you.

More frequent screening: If you're at high risk because of a strong family history of breast cancer, you and your doctor will develop a screening plan tailored to your unique situation. Recommended screening guidelines include:

• a monthly breast self-exam
• a yearly breast exam by your doctor or nurse practitioner
• a mammogram every year starting at age 40

Your personal screening plan also may include the following tests to detect any cancer as early as possible:

• MRI (magnetic resonance imaging) of the breast
• ultrasound

You may have these tests more often than a woman at average risk. So you might have one screening test -- a mammogram, say -- and then have a different test -- an MRI -- 6 months later. Before or after each screening test, your doctor may perform a breast exam. You also may start having these tests earlier than age 40.

Protective surgery: Removing one or both healthy breasts and ovaries -- called prophylactic surgery ("prophylactic" means "protective") -- are very aggressive, irreversible risk-reduction options that some women choose.

Prophylactic breast surgery may be able to reduce a woman's risk of developing breast cancer by as much as 97%. The surgery removes nearly all of the breast tissue, so there are very few breast cells left behind that could develop into a cancer.

Women with an abnormal BRCA1 or BRCA2 gene may reduce their risk of breast cancer by about 50% by having prophylactic ovary removal (oophorectomy) before menopause. Removing the ovaries lowers the risk of breast cancer because the ovaries are the main source of estrogen in a premenopausal woman's body. Removing the ovaries doesn't reduce the risk of breast cancer in postmenopausal women because fat and muscle tissue are the main producers of estrogen in these women. Prophylactic removal of both ovaries and fallopian tubes reduces the risk of ovarian cancer in women at any age, before or after menopause.

The benefit of prophylactic surgeries is usually counted one year at a time. That's why the younger you are at the time of surgery, the larger the potential benefit and the older you are, the lower the benefit. Also, as you get older you're more likely to develop other medical conditions that affect how long you live, such as diabetes and heart disease.

Of course, each woman's situation is unique. Talk to your doctor about your personal level of risk and how best to manage it.

It's important to remember that no procedure -- not even removing both healthy breasts and ovaries at a young age -- totally eliminates the risk of cancer. There is still a small risk that cancer can develop in the areas where the breasts used to be. Close follow-up is necessary, even after prophylactic surgery.

Prophylactic surgery decisions require a great deal of thought, patience, and discussion with your doctors, genetic counselor, and family over time -- together with a tremendous amount of courage. Take the time you need to consider these options and make decisions that feel comfortable to you.

For more information, visit the Breastcancer.org Prophylactic Mastectomy and Prophylactic Ovary Removal pages.

Think Pink, Live Green: A Step-by-Step Guide to Reducing Your Risk of Breast Cancer teaches you the biology of breast development and how modern life affects breast cancer risk. Download the PDF of the booklet to learn 31 risk-reducing steps you can take today.