Risk Factors: Genetic
About 5% to 10% of breast cancers are thought to be hereditary, caused by abnormal genes passed from parent to child.
If you’ve had one first-degree female relative (sister, mother, daughter) diagnosed with breast cancer, your risk is doubled. If two first-degree relatives have been diagnosed, your risk is 5 times higher than average.
Women with a father or brother who has had breast cancer also have a higher risk of breast cancer.