Breast Cancer Risk Factors

Breast Cancer Risk Factors:

Increasing age: As women grow older, their risk increases. Breast cancer is rare before the age of 30 and is most common in women older than 65. In fact, the biggest known risk factor is age.

History of previous breast cancer: A woman with a history of cancer in one breast has a higher chance of developing cancer in the other breast.

Family history of breast cancer: Close female relatives—a mother or sister, for example, increase a person's risk. Still, only about five to 10 percent of women who get breast cancer have a family history of the disease.

Absence of pregnancy: Both pregnancy and breast-feeding are associated with lowered risk and the earlier the pregnancy, the lower one's risk. Women who have a full pregnancy before the age of 18 have just one-third the breast cancer risk of women who give birth after age 30 or who have never had a child.