Breast cancer is the most commonly diagnosed cancer in women after skin cancer, and the second leading cause of cancer death in women (after lung cancer). While no one knows exactly why breast cancer develops, certain factors are known to increase your risk of this disease. It's also important to realize that some women with many risk factors never get breast cancer, and that the majority of women who do get the disease have few or no risk factors.

A woman can change some of her risk factors, but not others. For example, eating a healthy diet and getting regular exercise may lower you risk of breast cancer. On the other hand, just getting older and a family history of breast cancer cannot be modified.

The following table lists some of the factors that are recognized to increase or decrease your risk of breast cancer: