Breast Cancer Risk Factors You Cannot Change

A risk factor is anything that affects your chance of getting a disease, such as breast cancer. But having a risk factor, or even many, does not mean that you are sure to get the disease.

Some risk factors for breast cancer are things you cannot change, such as being a woman, getting older, and having certain gene changes. These make your risk of breast cancer higher.

Being a woman

Simply being a woman is the main risk factor for breast cancer. Men can get breast cancer, too, but this disease is about 100 times more common in women than in men.

Getting older

As you get older, your risk of breast cancer goes up. Most breast cancers are found in women age 55 and older.

Certain inherited genes

About 5% to 10% of breast cancer cases are thought to be hereditary, meaning that they result directly from gene defects (called mutations) passed on from a parent.

BRCA1 and BRCA2: The most common cause of hereditary breast cancer is an inherited mutation in the BRCA1 or BRCA2 gene. In normal cells, these genes help make proteins that repair damaged DNA. Mutated versions of these genes can lead to abnormal cell growth, which can lead to cancer.

• If you have inherited a mutated copy of either gene from a parent, you have a higher risk of breast cancer.
• On average, a woman with a BRCA1 or BRCA2 gene mutation has about a 7 in 10 chance of getting breast cancer by age 80. This risk is also affected by how many other family members have had breast cancer. (It goes up if more family members are affected.)  
• Women with one of these mutations are more likely to be diagnosed with breast cancer at a younger age, as well as to have cancer in both breasts. They also have a higher risk of developing some other cancers, mainly ovarian cancer.
• In the United States, BRCA mutations are more common in Jewish people of Ashkenazi (Eastern Europe) origin than in other racial and ethnic groups, but anyone can have them.

Changes in other genes: Other gene mutations can also lead to inherited breast cancers. These gene mutations are much less common, and most of them do not increase the risk of breast cancer as much as the BRCA genes.

• ATM: The ATM gene normally helps repair damaged DNA (or helps kill the cell if the damaged can't be fixed). Inheriting 2 abnormal copies of this gene causes the disease ataxia-telangiectasia. Inheriting one abnormal copy of this gene has been linked to a high rate of breast cancer in some families.
• TP53: The TP53 gene gives instructions for making a protein called p53 that helps stop the growth of abnormal cells. Inherited mutations of this gene cause Li-Fraumeni syndrome. People with this syndrome have an increased risk of breast cancer, as well as some other cancers such as leukemia, brain tumors, and sarcomas (cancers of bones or connective tissue). This mutation is a rare cause of breast cancer.
• CHEK2: The CHEK2 gene is another gene that normally helps with DNA repair. A CHEK2 mutation can increase breast cancer risk about 2-fold.
• PTEN: The PTEN gene normally helps regulate cell growth. Inherited mutations in this gene can cause Cowden syndrome, a rare disorder that puts people at higher risk for both non-cancer and cancer tumors in the breasts, as well as growths in the digestive tract, thyroid, uterus, and ovaries.
• CDH1: Inherited mutations in this gene cause hereditary diffuse gastric cancer, a syndrome in which people develop a rare type of stomach cancer. Women with mutations in this gene also have an increased risk of invasive lobular breast cancer.
• STK11: Defects in this gene can lead to Peutz-Jeghers syndrome. People affected with this disorder have pigmented spots on their lips and in their mouths, polyps (abnormal growths) in the urinary and digestive tracts, and a higher risk of many types of cancer, including breast cancer.
• PALB2: The PALB2 gene makes a protein that interacts with the protein made by the BRCA2 gene. Mutations in this gene can lead to a higher risk of breast cancer.

Mutations in several other genes have also been linked to breast cancer, but these account for only a small number of cases.

Genetic testing: Genetic testing can be done to look for mutations in the BRCA1 and BRCA2 genes (or less commonly in other genes such as PTEN or TP53). While testing can be helpful in some cases, not every woman needs to be tested, and the pros and cons need to be considered carefully.

One concern is that some genetic tests are promoted to doctors and the public without giving full information. For example, a test for a small number of BRCA1 and BRCA2 gene mutations has been approved by the FDA. However, there are more than 1,000 known BRCA mutations, and the ones included in the approved test are not the most common ones. This means there are many BRCA mutations that would not be detected by this test.

If you’re thinking about genetic testing, it’s strongly recommended that you first talk to a genetic counselor, nurse, or doctor who can explain these tests. It’s very important to understand what genetic testing can and can’t tell you, and to carefully weigh the benefits and risks of genetic testing before these tests are done. Testing costs a lot and might not be covered by some health insurance plans.

Our section on genetics and cancer has more information about genetic mutations and testing for them.

Having a family history of breast cancer

It’s important to note that most women (about 8 out of 10) who get breast cancer do not have a family history of the disease. But women who have close blood relatives with breast cancer have a higher risk:

• Having a first-degree relative (mother, sister, or daughter) with breast cancer almost doubles a woman’s risk. Having 2 first-degree relatives increases her risk about 3-fold.
• Women with a father or brother who have had breast cancer also have a higher risk of breast cancer.

Overall, less than 15% of women with breast cancer have a family member with this disease.

Having a personal history of breast cancer

A woman with cancer in one breast has a higher risk of developing a new cancer in the other breast or in another part of the same breast. (This is different from a recurrence or return of the first cancer.) Although this risk is low overall, it's even higher for younger women with breast cancer.

Your race and ethnicity

Overall, white women are slightly more likely to develop breast cancer than African-American women. But in women under age 45, breast cancer is more common in African-American women.

African-American women are also more likely to die from breast cancer at any age. Asian, Hispanic, and Native American women have a lower risk of developing and dying from breast cancer.

Having dense breast tissue

Breasts are made up of fatty tissue, fibrous tissue, and glandular tissue. Someone is said to have dense breasts (on a mammogram) when they have more glandular and fibrous tissue and less fatty tissue. Women with dense breasts on mammogram have a risk of breast cancer that is about 1.5 to 2 times that of women with average breast density. Unfortunately, dense breast tissue can also make it harder to see cancers on mammograms.

A number of factors can affect breast density, such as age, menopausal status, the use of certain drugs (including menopausal hormone therapy), pregnancy, and genetics.

Certain benign breast conditions

Women diagnosed with certain benign (non-cancer) breast conditions may have a higher risk of breast cancer. Some of these conditions are more closely linked to breast cancer risk than others. Doctors often divide benign breast conditions into 3 groups, depending on how they affect this risk.

Non-proliferative lesions: These conditions don’t seem to affect breast cancer risk, or if they do, the increase in risk is very small. They include:

• Fibrosis and/or simple cysts (sometimes called fibrocystic changes or disease)
• Mild hyperplasia
• Adenosis (non-sclerosing)
• Phyllodes tumor (benign)
• A single papilloma
• Fat necrosis
• Duct ectasia
• Periductal fibrosis
• Squamous and apocrine metaplasia
• Epithelial-related calcifications
• Other tumors (lipoma, hamartoma, hemangioma, neurofibroma, adenomyoepithelioma)

Mastitis (infection of the breast) is not a tumor and does not increase the risk of breast cancer.
Proliferative lesions without atypia (cell abnormalities): In these conditions there’s excessive growth of cells in the ducts or lobules of the breast, but the cells don't look very abnormal. These conditions seem to raise a woman’s risk of breast cancer slightly. They include:

• Usual ductal hyperplasia (without atypia)
• Fibroadenoma
• Sclerosing adenosis
• Several papillomas (called papillomatosis)
• Radial scar

Proliferative lesions with atypia: In these conditions, the cells in the ducts or lobules of the breast tissue grow excessively, and some of them no longer look normal. These types of lesions include:

• Atypical ductal hyperplasia (ADH)
• Atypical lobular hyperplasia (ALH)

Breast cancer risk is about 4 to 5 times higher than normal in women with these changes. If a woman also has a family history of breast cancer and either hyperplasia or atypical hyperplasia, she has an even higher risk of breast cancer.

Lobular carcinoma in situ (LCIS)
In LCIS, cells that look like cancer cells are growing in the lobules of the milk-producing glands of the breast, but they are not growing through the wall of the lobules. LCIS is also called lobular neoplasia. It’s sometimes grouped with ductal carcinoma in situ (DCIS) as a non-invasive breast cancer, but it differs from DCIS in that it doesn’t seem to become invasive cancer if it isn’t treated.

Women with LCIS have a much higher risk of developing cancer in either breast.

Starting menstruation (periods) early

Women who have had more menstrual cycles because they started menstruating early (especially before age 12) have a slightly higher risk of breast cancer. The increase in risk may be due to a longer lifetime exposure to the hormones estrogen and progesterone.

Going through menopause after age 55

Women who have had more menstrual cycles because they went through menopause later (after age 55) have a slightly higher risk of breast cancer. The increase in risk may be because they have a longer lifetime exposure to the hormones estrogen and progesterone.

Having radiation to your chest

Women who were treated with radiation therapy to the chest for another cancer (such as Hodgkin disease or non-Hodgkin lymphoma) when they were younger have a significantly higher risk for breast cancer. This varies with the patient’s age when they got radiation. The risk is highest if you had radiation as a teen or young adult, when your breasts were still developing. Radiation treatment after age 40 does not seem to increase breast cancer risk.

Exposure to diethylstilbestrol (DES)

From the 1940s through the early 1970s some pregnant women were given an estrogen-like drug called DES because it was thought to lower their chances of losing the baby (miscarriage). These women have a slightly increased risk of developing breast cancer. Women whose mothers took DES during pregnancy may also have a slightly higher risk of breast cancer.

Lifestyle-related Breast Cancer Risk Factors

A risk factor is anything that affects your chance of getting a disease, such as breast cancer. But having a risk factor, or even many, does not mean that you are sure to get the disease.

Certain breast cancer risk factors are related to personal behaviors, such as diet and exercise. Other lifestyle-related risk factors include decisions about having children and taking medicines that contain hormones.

Drinking alcohol

Drinking alcohol is clearly linked to an increased risk of breast cancer. The risk increases with the amount of alcohol consumed. Compared with non-drinkers, women who have 1 alcoholic drink a day have a very small increase in risk. Those who have 2 to 3 drinks a day have about a 20% higher risk compared to women who don’t drink alcohol. Excessive alcohol consumption is known to increase the risk of other cancers, too.

Being overweight or obese

Being overweight or obese after menopause increases breast cancer risk. Before menopause your ovaries make most of your estrogen, and fat tissue makes only a small amount. After menopause (when the ovaries stop making estrogen), most of a woman’s estrogen comes from fat tissue. Having more fat tissue after menopause can raise estrogen levels and increase your chance of getting breast cancer. Also, women who are overweight tend to have higher blood insulin levels. Higher insulin levels have been linked to some cancers, including breast cancer.

Still, the link between weight and breast cancer risk is complex. For instance, risk appears to be increased for women who gained weight as an adult, but may not be increased among those who have been overweight since childhood. Also, excess fat in the waist area may affect risk more than the same amount of fat in the hips and thighs. Researchers believe that fat cells in various parts of the body have subtle differences that may explain this.

Weight might also have different effects on different types of breast cancer. For example, some research suggests that being overweight before menopause might increase your risk of triple-negative breast cancer.

The American Cancer Society recommends you stay at a healthy weight throughout your life and avoid excess weight gain by balancing your food intake with physical activity.

Not being physically active

Evidence is growing that regular physical activity reduces breast cancer risk, especially in women past menopause. The main question is how much activity is needed. Some studies have found that even as little as a couple of hours a week might be helpful , although more seems to be better.

Exactly how physical activity might reduce breast cancer risk isn’t clear, but it may be due to its effects on body weight, inflammation, hormones, and energy balance.


The American Cancer Society recommends that adults get at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week (or a combination of these), preferably spread throughout the week.

Not having children

Women who have not had children or who had their first child after age 30 have a slightly higher breast cancer risk overall. Having many pregnancies and becoming pregnant at an early age reduces breast cancer risk. Still, the effect of pregnancy seems to be different for different types of breast cancer. For a certain type of breast cancer known as triple-negative, pregnancy seems to increase risk.

Not breastfeeding

Some studies suggest that breastfeeding may slightly lower breast cancer risk, especially if it’s continued for 1½ to 2 years. But this has been hard to study, especially in countries like the United States, where breastfeeding for this long is uncommon.

The explanation for this possible effect may be that breastfeeding reduces a woman’s total number of lifetime menstrual cycles (the same as starting menstrual periods at a later age or going through early menopause).

Birth control

Some birth control methods use hormones, which might increase breast cancer risk.

Oral contraceptives: Most studies have found that women using oral contraceptives (birth control pills) have a slightly higher risk of breast cancer than women who have never used them. Once the pills are stopped, this risk seems to go back to normal over time. Women who stopped using oral contraceptives more than 10 years ago do not appear to have any increased breast cancer risk.

Birth control shot: Depo-Provera is an injectable form of progesterone that’s given once every 3 months for birth control. Some studies have found that women currently using birth-control shots seem to have an increase in breast cancer risk, but it appears that there is no increased risk in women 5 years after they stop getting the shots.

Birth control implants, intrauterine devices (IUDs), skin patches, vaginal rings: These forms of birth control also use hormones, which in theory could fuel breast cancer growth. Some studies have shown a link between use of hormone-releasing IUDs and breast cancer risk, but few studies have looked at the use of birth control implants, patches, and rings and breast cancer risk.

When thinking about using hormonal birth control, women should discuss their other risk factors for breast cancer with their health care provider.

Hormone therapy after menopause

Hormone therapy with estrogen (often combined with progesterone) has been used for many years to help relieve symptoms of menopause and help prevent osteoporosis (thinning of the bones). This treatment goes by many names, such as post-menopausal hormone therapy (PHT), hormone replacement therapy (HRT), and menopausal hormone therapy (MHT).

There are 2 main types of hormone therapy. For women who still have a uterus (womb), doctors generally prescribe estrogen and progesterone (known as combined hormone therapy or HT). Progesterone is needed because estrogen alone can increase the risk of cancer of the uterus. For women who’ve had a hysterectomy (who no longer have a uterus), estrogen alone can be used. This is known as estrogen replacement therapy (ERT) or just estrogen therapy (ET).

Combined hormone therapy (HT): Use of combined hormone therapy after menopause increases the risk of breast cancer. It may also increase the chances of dying from breast cancer. This increase in risk can be seen with as little as 2 years of use. Combined HT also increases the likelihood that the cancer may be found at a more advanced stage.

The increased risk from combined HT appears to apply only to current and recent users. A woman’s breast cancer risk seems to return to that of the general population within 5 years of stopping treatment.

Bioidentical hormone therapy: The word bioidentical is sometimes used to describe versions of estrogen and progesterone with the same chemical structure as those found naturally in people. The use of these hormones has been marketed as a safe way to treat the symptoms of menopause. But because there aren’t many studies comparing “bioidentical” or “natural” hormones to synthetic versions of hormones, there’s no proof that they’re safer or more effective. More studies are needed to know for sure. The use of these bioidentical hormones should be considered to have the same health risks as any other type of hormone therapy.

Estrogen therapy (ET): The use of estrogen alone after menopause does not seem to increase the risk of breast cancer much, if at all. But when used long term (for more than 15 years), ET has been found to increase the risk of ovarian and breast cancer in some studies.

At this time there aren't many strong reasons to use post-menopausal hormone therapy (either combined HT or ET), other than possibly for the short-term relief of menopausal symptoms. Along with the increased risk of breast cancer, combined HT also appears to increase the risk of heart disease, blood clots, and strokes. It does lower the risk of colorectal cancer and osteoporosis, but this must be weighed against the possible harms, especially since there are other ways to prevent and treat osteoporosis, and screening can sometimes prevent colon cancer. ET does not seem to increase breast cancer risk, but it does increase the risk of stroke.

The decision to use HT should be made by a woman and her doctor after weighing the possible risks and benefits (including the severity of her menopausal symptoms), and considering her other risk factors for heart disease, breast cancer, and osteoporosis. If they decide she should try HT for symptoms of menopause, it’s usually best to use it at the lowest dose that works for her and for as short a time as possible.

Breast implants

Silicone breast implants can cause scar tissue to form in the breast. Implants make breast tissue harder to see on standard mammograms, but additional x-ray pictures called implant displacement views can be used to examine the breast tissue more completely.

Certain types of breast implants can be linked to a rare type of cancer called anaplastic large cell lymphoma (ALCL). It' is sometimes referred to as breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). This lymphoma appears to happen more often in implants with textured (rough) surfaces rather than smooth surfaces. If ALCL does show up after an implant, it can show up as a lump, a collection of fluid near the implant, pain, swelling or asymmetry (uneven breasts). It usually responds well to treatmen

A risk factor is anything that affects your chance of getting a disease, such as breast cancer. But having a risk factor, or even many, does not mean that you are sure to get the disease.

Certain breast cancer risk factors are related to personal behaviors, such as diet and exercise. Other lifestyle-related risk factors include decisions about having children and taking medicines that contain hormones.

Drinking alcohol

Drinking alcohol is clearly linked to an increased risk of breast cancer. The risk increases with the amount of alcohol consumed. Compared with non-drinkers, women who have 1 alcoholic drink a day have a very small increase in risk. Those who have 2 to 3 drinks a day have about a 20% higher risk compared to women who don’t drink alcohol. Excessive alcohol consumption is known to increase the risk of other cancers, too.

The American Cancer Society recommends that women who drink have no more than 1 drink a day.

Being overweight or obese

Being overweight or obese after menopause increases breast cancer risk. Before menopause your ovaries make most of your estrogen, and fat tissue makes only a small amount. After menopause (when the ovaries stop making estrogen), most of a woman’s estrogen comes from fat tissue. Having more fat tissue after menopause can raise estrogen levels and increase your chance of getting breast cancer. Also, women who are overweight tend to have higher blood insulin levels. Higher insulin levels have been linked to some cancers, including breast cancer.

Still, the link between weight and breast cancer risk is complex. For instance, risk appears to be increased for women who gained weight as an adult, but may not be increased among those who have been overweight since childhood. Also, excess fat in the waist area may affect risk more than the same amount of fat in the hips and thighs. Researchers believe that fat cells in various parts of the body have subtle differences that may explain this.

Weight might also have different effects on different types of breast cancer. For example, some research suggests that being overweight before menopause might increase your risk of triple-negative breast cancer.

The American Cancer Society recommends you stay at a healthy weight throughout your life and avoid excess weight gain by balancing your food intake with physical activity.

Not being physically active

Evidence is growing that regular physical activity reduces breast cancer risk, especially in women past menopause. The main question is how much activity is needed. Some studies have found that even as little as a couple of hours a week might be helpful , although more seems to be better.

Exactly how physical activity might reduce breast cancer risk isn’t clear, but it may be due to its effects on body weight, inflammation, hormones, and energy balance.


The American Cancer Society recommends that adults get at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week (or a combination of these), preferably spread throughout the week.

Not having children

Women who have not had children or who had their first child after age 30 have a slightly higher breast cancer risk overall. Having many pregnancies and becoming pregnant at an early age reduces breast cancer risk. Still, the effect of pregnancy seems to be different for different types of breast cancer. For a certain type of breast cancer known as triple-negative, pregnancy seems to increase risk.

Not breastfeeding

Some studies suggest that breastfeeding may slightly lower breast cancer risk, especially if it’s continued for 1½ to 2 years. But this has been hard to study, especially in countries like the United States, where breastfeeding for this long is uncommon.

The explanation for this possible effect may be that breastfeeding reduces a woman’s total number of lifetime menstrual cycles (the same as starting menstrual periods at a later age or going through early menopause).

Birth control

Some birth control methods use hormones, which might increase breast cancer risk.

Oral contraceptives: Most studies have found that women using oral contraceptives (birth control pills) have a slightly higher risk of breast cancer than women who have never used them. Once the pills are stopped, this risk seems to go back to normal over time. Women who stopped using oral contraceptives more than 10 years ago do not appear to have any increased breast cancer risk.

Birth control shot: Depo-Provera is an injectable form of progesterone that’s given once every 3 months for birth control. Some studies have found that women currently using birth-control shots seem to have an increase in breast cancer risk, but it appears that there is no increased risk in women 5 years after they stop getting the shots.

Birth control implants, intrauterine devices (IUDs), skin patches, vaginal rings: These forms of birth control also use hormones, which in theory could fuel breast cancer growth. Some studies have shown a link between use of hormone-releasing IUDs and breast cancer risk, but few studies have looked at the use of birth control implants, patches, and rings and breast cancer risk.

When thinking about using hormonal birth control, women should discuss their other risk factors for breast cancer with their health care provider.

Hormone therapy after menopause

Hormone therapy with estrogen (often combined with progesterone) has been used for many years to help relieve symptoms of menopause and help prevent osteoporosis (thinning of the bones). This treatment goes by many names, such as post-menopausal hormone therapy (PHT), hormone replacement therapy (HRT), and menopausal hormone therapy (MHT).

There are 2 main types of hormone therapy. For women who still have a uterus (womb), doctors generally prescribe estrogen and progesterone (known as combined hormone therapy or HT). Progesterone is needed because estrogen alone can increase the risk of cancer of the uterus. For women who’ve had a hysterectomy (who no longer have a uterus), estrogen alone can be used. This is known as estrogen replacement therapy (ERT) or just estrogen therapy (ET).

Combined hormone therapy (HT): Use of combined hormone therapy after menopause increases the risk of breast cancer. It may also increase the chances of dying from breast cancer. This increase in risk can be seen with as little as 2 years of use. Combined HT also increases the likelihood that the cancer may be found at a more advanced stage.

The increased risk from combined HT appears to apply only to current and recent users. A woman’s breast cancer risk seems to return to that of the general population within 5 years of stopping treatment.

Bioidentical hormone therapy: The word bioidentical is sometimes used to describe versions of estrogen and progesterone with the same chemical structure as those found naturally in people. The use of these hormones has been marketed as a safe way to treat the symptoms of menopause. But because there aren’t many studies comparing “bioidentical” or “natural” hormones to synthetic versions of hormones, there’s no proof that they’re safer or more effective. More studies are needed to know for sure. The use of these bioidentical hormones should be considered to have the same health risks as any other type of hormone therapy.

Estrogen therapy (ET): The use of estrogen alone after menopause does not seem to increase the risk of breast cancer much, if at all. But when used long term (for more than 15 years), ET has been found to increase the risk of ovarian and breast cancer in some studies.

At this time there aren't many strong reasons to use post-menopausal hormone therapy (either combined HT or ET), other than possibly for the short-term relief of menopausal symptoms. Along with the increased risk of breast cancer, combined HT also appears to increase the risk of heart disease, blood clots, and strokes. It does lower the risk of colorectal cancer and osteoporosis, but this must be weighed against the possible harms, especially since there are other ways to prevent and treat osteoporosis, and screening can sometimes prevent colon cancer. ET does not seem to increase breast cancer risk, but it does increase the risk of stroke.

The decision to use HT should be made by a woman and her doctor after weighing the possible risks and benefits (including the severity of her menopausal symptoms), and considering her other risk factors for heart disease, breast cancer, and osteoporosis. If they decide she should try HT for symptoms of menopause, it’s usually best to use it at the lowest dose that works for her and for as short a time as possible.

Breast implants

Silicone breast implants can cause scar tissue to form in the breast. Implants make breast tissue harder to see on standard mammograms, but additional x-ray pictures called implant displacement views can be used to examine the breast tissue more completely.

Certain types of breast implants can be linked to a rare type of cancer called anaplastic large cell lymphoma (ALCL). It' is sometimes referred to as breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). This lymphoma appears to happen more often in implants with textured (rough) surfaces rather than smooth surfaces. If ALCL does show up after an implant, it can show up as a lump, a collection of fluid near the implant, pain, swelling or asymmetry (uneven breasts). It usually responds well to treatment.

Breast cancer prevention: How to reduce your risk

Breast cancer prevention starts with healthy habits — such as limiting alcohol and staying physically active. Understand what you can do to reduce your breast cancer risk.

 If you're concerned about breast cancer, you might be wondering if there are steps you can take toward breast cancer prevention. Some risk factors, such as family history, can't be changed. However, there are lifestyle changes you can make to lower your risk.

What can I do to reduce my risk of breast cancer?

Lifestyle changes have been shown in studies to decrease breast cancer risk even in high-risk women. The following are steps you can take to lower your risk:

• Limit alcohol. The more alcohol you drink, the greater your risk of developing breast cancer. The general recommendation — based on research on the effect of alcohol on breast cancer risk — is to limit yourself to less than 1 drink per day as even small amounts increase risk.
• Don't smoke. Accumulating evidence suggests a link between smoking and breast cancer risk, particularly in premenopausal women. In addition, not smoking is one of the best things you can do for your overall health.
• Control your weight. Being overweight or obese increases the risk of breast cancer. This is especially true if obesity occurs later in life, particularly after menopause.
• Be physically active. Physical activity can help you maintain a healthy weight, which, in turn, helps prevent breast cancer. For most healthy adults, the Department of Health and Human Services recommends at least 150 minutes a week of moderate aerobic activity or 75 minutes of vigorous aerobic activity weekly, plus strength training at least twice a week.
• Breast-feed. Breast-feeding might play a role in breast cancer prevention. The longer you breast-feed, the greater the protective effect.
• Limit dose and duration of hormone therapy. Combination hormone therapy for more than three to five years increases the risk of breast cancer. If you're taking hormone therapy for menopausal symptoms, ask your doctor about other options. You might be able to manage your symptoms with nonhormonal therapies and medications. If you decide that the benefits of short-term hormone therapy outweigh the risks, use the lowest dose that works for you and continue to have your doctor monitor the length of time you are taking hormones.
• Avoid exposure to radiation and environmental pollution. Medical-imaging methods, such as computerized tomography, use high doses of radiation. While more studies are needed, some research suggests a link between breast cancer and radiation exposure. Reduce your exposure by having such tests only when absolutely necessary.

Can a healthy diet prevent breast cancer?

Eating a healthy diet might decrease your risk of some types of cancer, as well as diabetes, heart disease and stroke. For example, women who eat a Mediterranean diet supplemented with extra-virgin olive oil and mixed nuts might have a reduced risk of breast cancer. The Mediterranean diet focuses on mostly on plant-based foods, such as fruits and vegetables, whole grains, legumes and nuts. People who follow the Mediterranean diet choose healthy fats, like olive oil, over butter and fish instead of red meat.
Maintaining a healthy weight also is a key factor in breast cancer prevention.

Is there a link between birth control pills and breast cancer?

There's some evidence that hormonal contraception, which includes birth control pills and intrauterine devices (IUDs) that release hormones, increases the risk of breast cancer. But the risk is considered very small, and it decreases after you stop using hormonal contraceptives.
A recent study that indicated an association between hormonal contraceptive use and breast cancer determined one additional breast cancer could be expected for every 7,690 women who use hormonal contraception for at least one year.
Discuss your contraceptive options with your health care provider based on your particular needs. Also consider the benefits of hormonal contraception, such as controlling menstrual bleeding and reducing the risk of other cancers, including endometrial cancer and ovarian cancer.

What else can I do?

Be vigilant about breast cancer detection. If you notice any changes in your breasts, such as a new lump or skin changes, consult your doctor. Also, ask your doctor when to begin mammograms and other screenings based on your personal history.