Age. The risk of breast cancer increases with age. All women over age 40 are at risk.

Personal history of breast cancer. Women who have had breast cancer in one breast have an increased risk of developing breast cancer again.

Positive family history. A women’s risk of developing breast cancer increases if her mother, sister, daughter, or two or more other close relatives have had breast cancer.

Race. Breast cancer occurs more frequently in white women than in black or Hispanic women.

Late childbearing. Women who had their first child after the age of 30 have a greater chance of developing breast cancer than women who delivered at an earlier age.

Age of first menstruation. Women who first menstruated earlier than age 12 are at higher risk for breast cancer.

Gender. Although breast cancer can occur in men, 99% of all breast cancer is found in women.