A family history of certain types of cancer can increase your risk of breast cancer.
This increased risk may be due to genetic factors (known and unknown), shared lifestyle factors or other family traits.
Most women with breast cancer don't have a family history of the disease.
Only about 13 percent of women diagnosed have a first-degree female relative (mother, sister or daughter) with breast cancer .
A woman who has a first-degree female relative with breast cancer has almost twice the risk of a woman without this family history [111-113]. If she has more than 1 first-degree female relative with a history of breast cancer, her risk is about 3-4 times higher [111-113].
In general, the younger the relative was when she was diagnosed, the greater a woman's chance of getting breast cancer [24,113].
For example, a woman whose mother was diagnosed with breast cancer before age 40 has about twice the risk of a woman without this family history . For a woman whose mother was diagnosed at an older age, the increase in risk isn’t as high.
A history of breast cancer in a close male relative (father, brother or uncle) increases your risk of breast cancer .
A history of prostate cancer in 1 or more first-degree relatives (father or brother) may also increase a woman's risk of breast cancer, especially if the prostate cancer was found at a young age [114-116].
At this time, we don't know exactly why a family history of prostate cancer might increase breast cancer risk. However, some inherited gene mutations can increase risk of both cancers (see below).
The breast cancer risk linked to family history may be due to inherited gene mutations or shared lifestyle factors that increase risk.
Families with a strong history of breast cancer often carry gene mutations. Such families may have:
Inherited gene mutations account for only 5-10 percent of all breast cancers diagnosed in women in the U.S. [3,24].
Learn more about inherited gene mutations and breast cancer risk.
For a summary of research studies on inherited genetic mutations and breast cancer, visit the Breast Cancer Research Studies section.
There are special breast cancer screening guidelines for women with a strong family history of breast or ovarian cancer (for example, 2 or more first-degree relatives with breast cancer or 2 or more with ovarian cancer).
If you have a strong family history, the National Comprehensive Cancer Network recommends you get a :
If you have a first-degree relative who was diagnosed with breast or ovarian cancer before age 30, talk with your health care provider about when to start breast cancer screening.
This medical care helps ensure that if breast cancer does develop, it's caught early when the chances of survival are highest.
Learn more about breast cancer screening recommendations for women at higher risk.
Learn more about breast cancer screening recommendations for men at higher risk.
If you have a family history of breast or other type of cancer, your health care provider can help you understand how this impacts your risk of breast cancer.
My Family Health History tool
Learn more about talking with your health care provider.
Some people may not know their family medical history.
Risk assessment tools such as the Breast Cancer Risk Assessment Tool (Gail model) can estimate your breast cancer risk without this information. However, it will be less accurate without your family history details.
Talking with your health care provider about other risk factors for breast cancer can help you learn about your risk even if you don't have information on your family medical history.
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