A woman’s chance of developing breast cancer increases if she has close blood relatives with breast cancer. Breast can risk doubles if a woman’s mother, sister or daughter has breast cancer and her risk increases three-fold (triples) if she has 2 first degree relatives with breast cancer.
Women with a father or brother with breast cancer also have an increased risk of breast cancer. But it is not sure how much this adds to your risk. Less than 15% of women with breast cancer have a family member with this disease.