Age & Gender: The most prominent risk factors for breast cancer are age and gender. Men can develop breast cancer, but women are 200 times more likely to develop breast cancer than men. Breast cancer is four hundred times more common in women who are 50 years old as compared to those who are 20 years old. Seventy-five percent of women who develop breast cancer have no risk factors other than age.

Family History: A family history of breast cancer will increase the risk of developing breast cancer in a woman by three to five times.

Menstruation & Menopause: Women who started their menstrual periods before age 12, those who delayed menopause until after age 55, and those who had their first pregnancy after age 30 have a mildly increased risk of developing breast cancer (less than two times the normal risk).

Dietary Factors: Dietary factors such as high-fat diets and alcohol consumption have been implicated as increased risk factors for breast cancer in some studies. Studies that are more recent have disproved high-fat diets as increasing the risk for breast cancer.