This leads to a higher risk for breast cancer. Women who have their ovaries removed have less risk for breast cancer. All these factors revolve around estrogen balance. Another thing that increases risk is smoking. Changes can be seen on a breast biopsy, which show changes that might increase risk.
People often overlook family history.
Often they only look at their mother's side of the family. The father's side of the family is also important. Prostate, colon, uterine, ovarian, pancreatic and melanoma cancers should be looked at on both sides of the family. That might sound like a silly statement because removing the breast should reduce risk to zero, but in reality some cells may be left behind that could develop into cancer. As much breast tissue as possible needs to be removed to reduce the risk in high-risk women.