About 12% of American women have a family history of breast cancer. These women have a lifetime chance of breast cancer, about twice that of the general population. The lifetime risk for developing breast cancer in the general population is about 11-12% while it is 20-25% for those with a family history.
A family history means that two or more close family members (mother, sister, grandparent, or aunt) have or had breast cancer that was diagnosed before they turned 50. Family history on the father’s side is as important as that on the mother’s side. The more family members that are involved, the greater the risk of breast cancer. A family history of ovarian cancer is also considered a risk factor for breast cancer.
Most individuals or families with breast cancer do not have genetic mutations. But studies have shown that families with several members who have breast or ovarian cancer, particularly at an early age, are at increased risk for having a genetic mutation. It is important to know that a family history of cancer does not mean a person will get cancer. Many other factors may play a role. You should discuss with your doctor your risk for cancer and any additional screening tests you may need.