Breast Cancer - Prevention

You cannot control some things that put you at risk for breast cancer, such as your age and being female. But you can make personal choices that lower your risk of breast cancer. If you are at high risk for getting breast cancer, your doctor may also offer you certain medical treatments that can help prevent breast cancer.

Female hormones

Hormones change the way cells within the breast grow and divide. The years when you have a menstrual cycle are your high-estrogen years. Experts think that the longer you have higher estrogen, the more risk you have for breast cancer.⁸ This includes taking hormones after menopause.^{3, 17}

• The use of estrogen-progestin hormone therapy after menopause for several years or more increases your risk of developing breast cancer. But within 5 years after you stop using combined therapy, your risk returns to normal. Long-term use of estrogen alone may increase your risk for breast and ovarian cancer.⁷
• Breast-feed. Breast-feeding may lower your breast cancer risk. The benefit appears to be greatest in women who breast-fed for longer than 12 months or who breast-fed several children.¹⁸
• Strive for a healthy weight. Extra fat cells make extra estrogen, which raises your breast cancer risk.⁸ Getting regular exercise and watching what you eat can help.

Having a full-term pregnancy before age 30 also lowers your breast cancer risk.⁶

Healthy food and exercise

• Eat a healthy diet with plenty of fruits, vegetables, and whole grains.
• Be active. Try to do at least 2½ hours a week of moderate exercise. One way to do this is to be active 30 minutes a day, at least 5 days a week.^{19, 20} Staying active may lower your breast cancer risk.²¹
• Drink no more than one alcoholic drink a day.⁸ Using alcohol leads to extra estrogen in the body, which raises your breast cancer risk.⁶

If you are at high risk for breast cancer

If you are concerned that you may have an increased risk of developing breast cancer, talk with your doctor about whether you should take tamoxifen or raloxifene to lower your risk of breast cancer. It is important to consider both the benefits and risks of hormone therapy for breast cancer.

If you have a strong family history of early breast cancer or breast and ovarian cancer, talk to your doctor about BRCA testing. For more information, see:

Should I have a gene test for breast cancer?

What should I do if I'm at high risk for breast cancer?

Surgery to remove the breasts. Some women with a strong family history of breast cancer decide to have surgery to remove their breasts. This called a preventive or prophylactic mastectomy. It reduces the risk of developing breast cancer by approximately 90% in women who have a strong family history of breast cancer. A cancer risk assessment, genetic test, and psychological counseling are recommended for women who may be considering this treatment option.

Surgery to remove the ovaries.Genetic mutations (called BRCA1 or BRCA2 gene changes) raise the risk of both breast cancer and ovarian cancer. Hormones made by the ovaries increase the risk of breast cancer. Removal of the ovaries (prophylactic oophorectomy) reduces the risk of breast or ovarian cancer in women with a genetic mutation. Such a decision is best made after a cancer risk assessment, genetic test, and counseling.

Should I have my ovaries removed to prevent ovarian cancer?