This is the most common type of cancer in American women. About one in every eight women develops breast cancer. However, surgery often involves removing all or part of the breast. When abnormal cells grow uncontrollably, they are called cancers. It is not known why cancers occur.
Some women are more likely to get breast cancer than others.
You have never breast-fed a baby or you had your first child after age 30. You started your menstrual period very early or you went through menopause very late. Taking birth control pills and oral estrogen does not seem to increase the risk of breast cancer. Most women find the lump themselves during a breast self-exam. Usually the lump is painless and it may be difficult to feel at first.