Preventive Surgery to Reduce Breast Cancer Risk

Some women with a very high risk of breast cancer may choose preventive surgery to remove their breasts. This surgery is called a prophylactic mastectomy. (Prophylactic means something used to prevent disease.)

Should I consider surgery to lower my risk of breast cancer?

You might consider preventive surgery if you:

• Have a mutation in the BRCA1 or BRCA2 gene (or certain other genes that increase breast cancer risk) that is found by genetic testing
• Have a strong family history of breast cancer (such as breast cancer in several close relatives, or breast cancer in at least one relative at a young age)
• Had radiation therapy to the chest before age 30
• Have (or have had) cancer in one breast (especially if you also have a strong family history)

Like any type of surgery, a mastectomy can have risks and side effects, some of which could affect your quality of life. Because of this, preventive surgery is not usually a good option for women who are at average risk of breast cancer, or for those who are at only slightly increased risk.

For women who are known (or strongly suspected) to have a BRCA1 or BRCA2 gene mutation, a prophylactic oophorectomy (removal of the ovaries) might be recommended as well.

Prophylactic mastectomy

A prophylactic mastectomy is surgery to remove one or both breasts to lower the chances of getting breast cancer. There are different types of mastectomies that might be options.

A prophylactic mastectomy can lower breast cancer risk by 90% or more, but it doesn’t guarantee that you will not get breast cancer. This is because it's not possible to remove all breast cells, even with a mastectomy. The breast cells that are left behind might still go on to become cancer.

A prophylactic mastectomy might be considered in two main situations.

For women at very high risk of breast cancer

For women in this group, removing both breasts (known as a bilateral prophylactic mastectomy) before cancer is diagnosed can greatly reduce (but not eliminate) the risk of getting breast cancer. 

Unfortunately there’s no way to know for sure ahead of time if a woman will benefit from this surgery. Most women with a BRCA1 or BRCA2 gene mutation will develop breast cancer at some point. Having a prophylactic mastectomy before the cancer develops might add many years to their lives. But not all women with BRCA1 or BRCA2 mutations develop breast cancer. For some women the surgery might not have been helpful. Although they might still get some important benefits from the surgery such as peace of mind, they would also have to deal with its aftereffects, which might include physical and emotional side effects.

For women already diagnosed with breast cancer

Some women who have already been diagnosed with breast cancer choose to have the other breast removed at the same time of surgery to remove the breast with cancer. This operation (known as a contralateral prophylactic mastectomy, or CPM) can help lower their risk of developing a second breast cancer. 

This is more likely to be a good option for women who also have other factors that increase their risk of getting another breast cancer, such as a BRCA1 or BRCA2 mutation or a strong family history of breast cancer.

But for women who don't have a family history or other risk factors for breast cancer, the benefit of CPM is less clear. Having breast cancer does raise your risk of getting cancer in the other breast, but this risk is still usually low, and many women overestimate this risk. And while CPM lowers the risk of getting cancer in the other breast, it does not increase most women's chances of living longer.  

Other issues might also be important when considering a CPM. For example, after a mastectomy, the breasts may no longer look the same, even if a woman has breast reconstruction. Removing both breasts (possibly followed by reconstruction) can help the breasts look more symmetrical after treatment.

Before having this type of surgery, it’s very important to talk with a member of your cancer care team or a genetic counselor so that you understand how much you might benefit from it, versus the likelihood of risks and side effects. You might also want to get a second medical opinion, as well as talk to others who have had this surgery, before deciding if it’s right for you.

Prophylactic oophorectomy (removal of the ovaries)

Women with a BRCA1 or BRCA2 mutation have a high risk of developing breast cancer and ovarian cancer. 

Most doctors recommend that women with a BRCA1 or BRCA2 mutation have surgery to remove their ovaries (and usually the attached fallopian tubes as well) once they’ve finished having children. This operation, known as a prophylactic oophorectomy, greatly reduces the risk of ovarian cancer. Some studies have suggested it might lower the risk of breast cancer as well, although not all studies have found this. Some women choose to have this surgery done along with a prophylactic mastectomy.

Removing the ovaries causes a woman to go into menopause. This can lead to symptoms such as hot flashes, trouble sleeping, vaginal dryness, loss of bone density, and anxiety or depression. 

Again, it’s important to talk to your health care team so that you’re well informed about the possible benefits, risks, and side effects of this type of surgery. You might also want to talk to other women who have had this surgery before deciding if it’s right for you.

Other options to reduce breast cancer risk

If you’re concerned about your breast cancer risk, talk to your health care provider. They can help you estimate your risk based on your age, family history, and other factors. If you are at increased risk, you might consider taking medicines that can help lower your risk. Your health care provider might also suggest you have more intensive screening for breast cancer, which might include starting screening at a younger age or having other tests in addition to mammography.

There are also other things that all women can do to help lower their risk of breast cancer, such as being active, staying at a healthy weight, and limiting or not drinking alcohol. For more information, see Can I Lower My Risk of Breast Cancer?