FALSE. More than 75% of women with breast cancer have no family history of the disease and less than 10% have a known gene mutation that increases risk.
If you have relatives who have had breast cancer, you may worry that you’re next. Family history of breast cancer usually refers to having two or more first-degree relatives (such as a mother, sister, or daughter) or second-degree relatives (such as an aunt, niece or grandmother) who have had breast cancer. The risk for developing breast cancer does increase with increasing numbers of affected first-degree relatives compared with women who have no affected relatives. So, while it is true that women with a family history of breast cancer have an increased risk of developing the disease, most of these women will never get breast cancer.
We have discovered that, among some women with a significant family history, certain inherited mutations of the genes BRCA 1 and BRCA 2 may result in increased risk of breast cancer. The mutations are sometimes (but not always) passed down to relatives. Even if you have a family history, it does not mean you have an inherited mutation.