Most women are not at high risk for breast cancer. But some women have a high risk because they have what is called a family history of breast cancer. That means they have one or more relatives with breast cancer. If anyone in your family has had breast cancer, your doctor can help you figure out how much that affects your chances of getting breast cancer yourself.

Your risk depends on what kind of family history you have. For example, having one relative with breast cancer gives you a family history. But if you have two close relatives—like your mother and your sister—with breast cancer, and one of them was diagnosed before age 50, your family history is stronger and your risk of getting breast cancer is higher.

A few women are at very high risk because they have inherited a gene change that makes them very likely to get breast cancer. The only way to find this out is to have a breast cancer gene test. The test looks for changes, or mutations, in two genes that are related to breast and ovarian cancer. The two genes are called BRCA1 and BRCA2 (BRCA stands for BReast CAncer). Changes in these BRCA (say "BRAH-kuh") genes are rare, but having one greatly increases your chances of getting breast and ovarian cancer. These women usually have a strong family history of breast cancer, also.

To understand the effect that a family history of breast cancer can have on your chances of getting the disease, consider the numbers below. It’s important to remember that everyone’s case is different and that these numbers may not show what will happen in your case.

• Out of 100 average women, about 12 will get breast cancer sometime during their lives.
• Out of 100 women with a family history of breast cancer, between 24 and 60 will get breast cancer sometime during their lives, depending on how strong their family history is.¹ To put it another way, having a family history makes you 2 to 5 times more likely to get breast cancer than the average woman.
• Out of 100 women who have inherited a breast cancer gene, between 36 and 85 will get breast cancer sometime during their lives.² To put it another way, having a BRCA gene change makes you 3 to 7 times more likely to get breast cancer than the average woman.

Breast cancer risk: Should I have a BRCA gene test?

Sometimes women think that their risk is higher than it really is. These women may end up having drastic surgery that they don't need. That's why it's very important to know how high your personal risk for breast cancer is. Talk to your doctor.

When you know how high your risk is, you can begin to think about what steps you want to take—if any—to prevent cancer. These are the choices:

• Extra checkups and testing. Having checkups and testing more often may help find the cancer earlier, when it's easier to treat.
• Medicines.Taking certain anti-cancer drugs may help some women prevent breast cancer.
• Surgery to remove both breasts.This operation helps prevent most breast cancer.
• Surgery to remove the ovaries. This operation helps prevent both ovarian and breast cancer.

The choices will be different depending on how high your risk is. For example, a woman with a BRCA gene change may want to think about having both of her breasts and her ovaries removed because she is at much higher risk. But surgery may not be a good choice for a woman who has a family history with no gene change. Her risk is not as high, and surgery might be too drastic for her.

You may choose more than one of these options. You may choose only to have extra checkups and testing. Your decision may change over time. For example, some women will decide to choose extra checkups and testing now and think about surgery later, after they have had children and have finished breast-feeding.

All women should have regular checkups and tests for breast cancer. But if you are at high risk, you may need to do this more often. You may also need to start younger, or have additional screening tests. This is sometimes called "intensive surveillance" or "intensive screening." The goal is to find breast cancer as early as possible so that it can be treated.

Talk with your doctor about the screening tests and schedules that would be best for you. For high-risk women, this may mean:

• Going to the doctor for checkups 1 or 2 times a year.
• Having a mammogram every year, even if you are younger than 40.
• Letting your doctor know if you notice anything unusual in your breast.

Depending on your situation, your doctor may also want you to have an MRI scan every year. MRIs may do a better job at finding breast cancer early, especially in women who have inherited a changed BRCA gene or have two or more close family members who have had breast cancer before age 50.³ MRI may also be used to check the other breast in women diagnosed with breast cancer.⁴

Tamoxifen (say "tuh-MOK-suh-fen") is a medicine that blocks the effect of estrogen on breast cancer cells and normal breast cells. Studies show that taking tamoxifen for 5 years greatly lowers the chance of breast cancer in women who are at high risk because of family history, age, and other factors.

Another drug, raloxifene (say "ral-OX-ih-feen"), has been approved for high-risk women who are past menopause. Studies done so far show that raloxifene works about as well as tamoxifen to prevent breast cancer. But raloxifene has not been studied in women with BRCA changes.

Your doctor can help you decide if taking one of these medicines is right for you.

Having your breasts removed greatly lowers your chances of getting breast cancer, because it removes almost all of the breast tissue.⁵ But it is not yet known whether this surgery is better than having careful screening and then treatment if any breast cancer develops.⁶

An operation to remove a breast is called a mastectomy (say "mass-TEK-tuh-mee"). When both breasts are removed, it is called a bilateral mastectomy. Bilateral means "both sides."

Some women have their breasts reconstructed during the same operation. Breasts can also be reconstructed later.

Having your breasts removed does not guarantee that you won't get breast cancer. This is because no operation can remove every bit of breast tissue.⁶

Having your ovaries removed lowers your chances of getting breast cancer.^{7, 8} The ovaries produce a woman's eggs as well as certain hormones, like estrogen. Estrogen seems to increase a woman's chances of getting breast cancer. That may be why having your ovaries removed lowers your chances.

Experts recommend that women who have BRCA gene changes consider surgery to remove their ovaries and fallopian tubes when they are done having children, or between the ages of 35 and 40.⁹ This decreases their risk of getting cancer in the breasts and the ovaries.

The surgery to remove the ovaries is called an oophorectomy (say "oh-uh-fuh-REK-tuh-mee").

When your ovaries are removed, you can no longer get pregnant. Also, your body's supply of estrogen and other hormones will end, and you will go into early menopause.

Menopause symptoms include hot flashes and vaginal dryness. Although many women in menopause take hormone therapy to control these symptoms, hormone therapy may increase the risk of breast cancer. So it is not recommended if you are having your ovaries removed to help prevent breast cancer.

You and your doctor can't begin to decide what steps you should take to prevent breast cancer until you know how high your personal risk is. If you don't know how high your risk is, talk to your doctor. He or she will help you find out.

The higher your risk, the more you and your doctor may want to consider surgery.

Sometimes women think that their risk is higher than it really is. These women may end up having drastic surgery that they don't need. That's why it's very important to know how high your personal risk for breast cancer is. Talk to your doctor.