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Breast Cancer Risk Factors You Cannot Change
A risk factor is anything that increases your chances of getting a disease, such as breast cancer. But having a risk factor, or even many, does not mean that you will get cancer.
There are some risk factors for breast cancer that you cannot change, such as age, sex, or inheriting certain gene changes. These make your risk of breast cancer higher.
On this page
Sex
Being born female is the main risk factor for breast cancer. People born male can get breast cancer, too, especially if they have a BRCA gene change (mutation) or family history of male breast cancer. However, this disease is much more common in those born female.
Age
As you get older, your risk of breast cancer increases. Most breast cancers are found in women age 55 and older.
Race and ethnicity
In the United States, breast cancer is most common among white females. However, breast cancer is the most common type of cancer in women across all races and ethnicities.
Under age 40, breast cancer is more common in African American women. African American women are also more likely to die from breast cancer at any age. And they are more likely to have the less common triple-negative breast cancer.
Asian, Hispanic, and American Indian women have a lower risk of developing and dying from breast cancer.
Women of Ashkenazi Jewish descent are more likely to be affected by hereditary breast and ovarian cancer (HBOC) syndrome. They also have a higher risk of breast and ovarian cancer related to gene changes in BRCA1 or BRCA2.
Adult height
Many studies have found that taller women have a higher risk of breast cancer than shorter women. The reasons for this aren’t exactly clear. This may be related to factors that affect early growth. These may include nutrition early in life and hormonal and genetic factors.
Genetic syndromes
Up to 10% of breast cancer cases are thought to be hereditary. This means that they are caused by gene changes (mutations) passed in families.
Gene testing may be recommended by your care team depending on your personal and family history of cancer. This might be an option for some people who have been diagnosed with breast cancer. It might also be an option for people with factors that put them at higher risk for breast cancer, such as a strong family history. Talk to your health care team about whether genetic testing could be right for you.
While genetic testing can be helpful in some cases, not everyone needs to be tested. The benefits and risks of genetic testing need to be considered carefully. To learn more, see Genetic Counseling and Testing for Breast Cancer Risk.
Changes in these genes cause Hereditary Breast and Ovarian Cancer syndrome. They are the most common inherited cause of breast cancer. BRCA genes are tumor suppressor genes, which work by blocking abnormal cell growth. When one of these genes does not work properly, or is mutated, cancer is more likely to develop.
Risk of breast cancer
On average, a woman with a BRCA1 or BRCA2 gene change has up to a 70 in 100 chance of being diagnosed with breast cancer over her lifetime.
Breast cancer is rare in men, but having a BRCA gene change can significantly raise the lifetime risk. Learn more about how inherited gene changes can affect men.
Features of BRCA1 or BRCA2 breast cancers
People with one of these gene changes are more likely to:
- Have cancer in both breasts
- Be diagnosed with breast cancer at a younger age
Increased risk of other types of cancer
People with BRCA1 or BRCA2 gene changes can have an increased risk of other types of cancer as well. These include:
- Ovarian (females)
- Prostate (males)
- Pancreatic
- Colorectal
The TP53 gene helps stop cells with damaged DNA from growing. When the gene is changed, damaged cells grow and can cause cancer. Inherited mutations (changes) of this gene cause Li-Fraumeni syndrome. People with this syndrome have an increased risk of breast cancer. They also have a higher risk for other cancers such as leukemia, brain tumors, and sarcomas (cancers of bones or connective tissue). This mutation is a rare cause of breast cancer.
Changes in the STK11 gene can lead to Peutz-Jeghers syndrome. People with this disorder often have pigmented spots on their lips and in their mouths and polyps (abnormal growths) in the urinary and digestive tracts. And they have a higher risk of many types of cancer, including breast cancer.
The PTEN gene normally helps regulate cell growth. Inherited mutations (changes) in this gene can cause Cowden syndrome. This is a rare disorder that puts people at higher risk for both cancer and benign (noncancerous) tumors in the breasts, as well as growths in the digestive tract, thyroid, uterus, and ovaries.
Inherited mutations (changes) in this gene cause people to develop a rare type of stomach cancer. Women with mutations in this gene also have an increased risk of invasive lobular breast cancer.
The ATM gene repairs damaged DNA or directs the cell to die if the damage can't be fixed. Inheriting 2 abnormal copies of this gene causes the disease ataxia-telangiectasia (A-T). Inheriting one abnormal copy of this gene has been linked to a high rate of breast cancer in some families.
Neurofibromatosis type 1 (NF1) is caused by a change in the NF1 gene, which helps control cell growth. When the NF1 gene does not work properly, tumors can form.
People with this gene change can have tumors grow on their nerves. They may also have skin changes. Most tumors in people with NF1 gene changes are benign (not cancer). However, certain cancers like breast cancer happen more often in people with this gene change.
The PALB2 gene makes a protein that works with the protein made by the BRCA2 gene. Mutations (changes) in this gene can lead to a higher risk of breast cancer. People with this mutation are more likely to have estrogen-receptor negative breast cancer. They also have a higher risk of estrogen-receptor positive breast cancer.
The CHEK2 gene is another gene that normally helps with DNA repair. A CHEK2 mutation (change) increases breast cancer risk.
The BARD1 gene makes a protein that works with the protein made by the BRCA1 gene. On average, up to 3 out of 10 women with a BARD1 gene change can develop breast cancer.
The protein made by the RAD51C gene works by fixing damaged DNA. If the protein doesn’t work properly, then abnormal cells are able to grow. This can lead to cancer. About 1 in 5 women with this gene change will develop breast cancer in their lifetime. This gene change also increases the risk of having ovarian cancer.
The protein made by the RAD51D gene works by fixing damaged DNA. If the protein doesn’t work properly, then abnormal cells are able to grow. This can lead to cancer. About 1 in 5 women with this gene change will develop breast cancer in their lifetime. This gene change also increases the risk of having ovarian cancer.
Family history of breast cancer
Breast cancer in first-degree relatives, such as your mother, sister or daughter affects your personal breast cancer risk. Having one first-degree relative with breast cancer almost doubles a woman’s risk. Having 2 first-degree relatives with breast cancer can triple the risk of developing breast cancer.
The age that your first-degree relative was diagnosed with breast cancer can affect your breast cancer risk as well. For example, a single first-degree relative with breast cancer diagnosed before age 30 triples your risk. A first-degree relative diagnosed after age 60 increases your risk, but by much less than having a younger relative with breast cancer.
If a male first-degree relative (father or brother) had breast cancer, this also increases your risk of breast cancer.
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.
Dense breast tissue
Breasts are made up of fatty tissue, fibrous tissue, and glandular tissue. Breasts that have more glandular and fibrous tissue and less fatty tissue appear dense on a mammogram.
Women with dense breasts on breast imaging have a higher risk of breast cancer than women with average breast density. Dense breast tissue can also make it harder to see cancers on mammograms.
A number of factors can affect breast density. These include:
- Age
- Menopausal status
- Use of certain medicines, including menopausal hormone therapy
- Exercise
- Diet
- Pregnancy
- Genetics
To learn more, see our information on breast density and mammograms.
Benign breast conditions
Women diagnosed with certain types of benign (noncancerous) breast conditions may have a higher risk of breast cancer. Some of these conditions are more closely linked to breast cancer risk than others. Healthcare teams often divide benign breast conditions into different groups, depending on how they affect the risk of cancer.
In these conditions, cells in the ducts or lobules of the breast grow more than usual. However, when looked at under a microscope, the cells don't look very different from healthy cells. These conditions might raise a woman’s risk of breast cancer slightly. They include:
- Usual ductal hyperplasia (without atypia)
- Complex fibroadenoma
- Sclerosing adenosis
- Several papillomas (called papillomatosis)
- Radial scar
In these conditions, the cells in the ducts or lobules of the breast tissue grow too much. And some of these cells no longer look normal. These types of lesions include:
Someone with these changes is about 4 to 5 times more likely to develop breast cancer. If that person also has a family history of breast cancer and either hyperplasia or atypical hyperplasia, they have an even higher risk of breast cancer.
LCIS is not cancer, but rather a pre-cancer. Abnormal cells grow in the lobules of the milk-producing glands of the breast, but they do not grow through the wall of the lobules. Even though LCIS is not cancer, having LCIS increases the risk of developing breast cancer in the future. Someone with LCIS has a 7 to 12 times higher risk of developing breast cancer in either breast.
For more on these conditions, see Non-cancerous Breast Conditions.
These conditions don’t seem to affect breast cancer risk. If they do, the increase in risk is very small. They include:
- Fibrosis and/or simple cysts (sometimes called fibrocystic changes)
- Mild hyperplasia
- Adenosis (non-sclerosing)
- Phyllodes tumor (benign)
- A single papilloma
- Fat necrosis
- Duct ectasia
- Periductal fibrosis
- Pseudoangiomatous stromal hyperplasia (PASH)
- 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.
Early menstruation and/or late menopause
Women who have had more menstrual cycles have a slightly higher risk of breast cancer. This can happen if they started menstruating early, especially before age 12. Or it can happen if they went through menopause later, such as after age 55.
This higher risk is similar to women who have never been pregnant. The increase in risk may be due to lifetime exposure to estrogen and progesterone hormones.
Having radiation to your chest
Women who were treated with radiation therapy to the chest for another cancer when they were younger have a significantly higher risk for breast cancer. This risk depends on a person’s age at the time of treatment. The risk is highest if you had radiation as a teen or young adult, when the breasts were still developing. Radiation treatment after about age 40 to 45 does not seem to increase breast cancer risk.
Exposure to diethylstilbestrol (DES)
From the 1940s through the early 1970s, some pregnant people were given an estrogen-like drug called DES. It was thought this drug would lower the chances of losing the baby (miscarriage). These people have a slightly increased risk of developing breast cancer. People whose mothers took DES while they were pregnant with them may also have a slightly higher risk of breast cancer.
More resources
Learn more about risk factors for breast cancer.
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- References
Developed by the P站视频 medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
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Last Revised: March 24, 2026
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