How does having a family history of breast cancer affect my chances of developing breast cancer?
Under 10% of breast cancer cases are genetically inherited. In other words, most women diagnosed with breast cancer do not have a family history of the disease. If you have a first-degree relative (a mother, daughter or sister) who has had breast cancer, you have an increased risk of developing breast cancer. If you have a family history with one or more first-degree relatives that have had cancer in both breasts (bilateral breast cancer), particularly arising before menopause, this could be an indication of genetically inherited breast cancer. A genetic counselor can help you assess your risk, and the risk of other women in your family.
