Breast Cancer


This is a growth of cancer cells in your breast. It is the most common form of cancer in women after skin cancer. It affects one woman in eight during their lives. Men can also have breast cancer, but it's rare.


We aren't sure what causes breast cancer. It starts with a mutation in a cell's DNA. These are the genetic blueprints that tell cells how to grow and function. The mutation makes the cell divide abnormally and uncontrollably. A tumor is a mass of these abnormal cells. Tumors that don't invade other tissues are called "benign." They are not cancer. Tumors that spread into other tissues are called "malignant." This is cancer.

Risk Factors

Many things can raise a woman's risk for breast cancer. Your risk gets higher as you get older. It's higher if certain genetic traits are passed down to you from your parents. You're more likely to get breast cancer if you begin your periods early or go through menopause late. It's higher if you have dense breasts. Not having children, or having your first child after age 35 increases your risk. So does being overweight, drinking alcohol, and taking birth control pills or hormone replacement therapy.


In women, breast cancer most often starts in the cells of the milk ducts or the lobules. The milk ducts are the passageways that carry milk to the nipple. The lobules are the glands that make milk.


A lump in your breast may be a sign of cancer. You may feel a lump under your arm. Your breast may swell. It may change size or shape. The skin may be red and flaky. You may feel pain in your breast. Fluid may come out of your nipple. It may be clear, it may be green or yellow, or it may look bloody.

Treatment and Screening

Treatment depends on the type of cancer you have and your needs. You may benefit from surgery, chemotherapy, or radiation. You may benefit from hormone therapy or biological therapy. Catching cancer early is important. Have regular breast cancer exams. Learn to do self-exams properly. And talk with your doctor about breast cancer screening.