What does it mean for my breast cancer risk if my mother had breast cancer?

Breast cancer risk is higher among women whose close blood relatives have this disease.

Having one first-degree relative (mother, sister, or daughter) with breast cancer approximately doubles a woman's risk. Having two first-degree relatives increases her risk about five-fold.

Altogether, about 20% to 30% of women with breast cancer have a family member with this disease. This means that most (70% to 80%) women who get breast cancer do not have a family history of this disease. And certainly not all women with a family history get breast cancer.

Breast cancer risk is increased with familial history.  In general, having one 1st degree relative on the maternal side, including the sister, mother or daughter, will double your risk and, again, this can increase by five fold in women who have two 1st degree relatives with breast cancer.  Women who have strong family diathesis of breast cancer at higher risk need to be screened regularly in order to prevent, survey and treat accordingly.

Having a mother or sister with breast cancer (first-degree relative) does generally increase risk of breast cancer to 2-3 times that of the general population. It is important to look at the entire family history to see whether there is a possibility of a genetic syndrome in the family. However other factors, including mother’s age at diagnosis, also affect specific risk estimates. A visit with a genetic counselor or breast cancer specialist can help clarify your individualized risk.