> Family History of Breast, Ovarian or Prostate Cancer
Family history is an important risk factor for breast cancer. Having one immediate female family member (mother, sister or daughter) with breast cancer almost doubles a woman's chance of developing breast cancer compared to a woman with no family history. If a woman has more than one immediate female family member with a history of breast cancer, her chances are increased by about three to four times compared to a woman with no female family history [28,29]. For information about the risk related to having a male relative with breast cancer, see information below.
In general, the younger her relative was when diagnosed with breast cancer, the greater a woman's chance of getting the disease [29]. A woman whose mother was diagnosed with breast cancer before age 50 has about twice the risk of the disease than a woman with no immediate family members with breast cancer [29]. For a woman whose mother was diagnosed after age 50, the increase in risk isn't as great.
When talking about family history, it's also important to consider the men in your family. A history of breast cancer in a close male relative (father, brother, uncle), though rare, can significantly increase breast cancer risk. A history of prostate cancer in one or more immediate family members (father or brother) may also increase risk, especially if cancer was found at an early age [30-32]. Exactly why a family history of prostate cancer may increase breast cancer risk isn't known yet, though the risk of both cancers is influenced by blood hormone levels.
While the increases in risk linked to family history may be due to family lifestyle factors, it can also be associated with specific genetic mutations that can increase for the risk of breast cancer. This is especially so in families with a strong family history of breast cancer, such as multiple immediate family members (mother or sister) with breast cancer or a single immediate family member diagnosed at an early age. Family history of ovarian cancer also raises suspicion of an inherited genetic mutation. Learn more about inherited genetic mutations and breast cancer risk.
Some people may not know their family medical history in detail. Risk assessment tools such as the Gail model can estimate a person's breast cancer risk without this information. However, the estimate will be less accurate without family history details. Talking with a health care provider about other risk factors can help a person without family medical information learn what can be done to reduce his/her breast cancer risk.
Updated 05/20/09
