MONDAY, Oct. 31 (HealthDay News) -- Women who have a relative with breast cancer linked to the high-risk BRCA genetic mutation understandably worry about their own risk.
Now, a new study suggests that women who don't test positive for the mutations are not at an extremely high risk of getting breast cancer, even if they have a relative with BRCA-related breast cancer.
Their risk is similar to that of women with relatives with non-BRCA-related cancers, the new research indicates.
This refutes a finding from a 2007 study, which found a two- to five-times higher risk for these women, even if they tested negative for the mutations, said senior study author Dr. Alice S. Whittemore, a professor of health research and policy at Stanford University School of Medicine.
Based on the new research, she said, the bottom line is this: "If you are in a family where there is a BRCA mutation and you do not have that mutation, your risk of breast cancer is no greater than anyone with a family history of [other types of] breast cancer."
According to the American Cancer Society, having one first-degree relative, such as a mother, sister or daughter, with breast cancer doubles a woman's risk of getting it. Having two close relatives increases the risk about threefold.
Whittemore calls the new finding "very, very reassuring" because it suggests that having a family history of the BRCA mutation, by itself, is not a risk factor, she said.
The study is published online Oct. 31 in the Journal of Clinical Oncology.
Women with a BRCA1 or BRCA 2 gene mutation have a 5- to 20-fold higher risk of getting breast or ovarian cancer, the Stanford researchers wrote. That means a lifetime probability of up to 65 percent for breast cancer, and up to 40 percent for ovarian cancer.
Women who have the BRCA1 and BRCA2 mutations and are cancer-free are urged to step up th
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