Breast cancer facts:
- Breast cancer is the most frequently diagnosed cancer (other than skin cancer) in women. It affects hundreds of thousands of women in the United States each year, including more than 200,000 newly diagnosed cases.
- A woman's risk of developing breast cancer over her lifetime is 1 in 8, or 12 percent.
- A breast cancer can be found on a mammogram, or it can be felt by the woman herself or by her physician. Not all breast cancers can be detected by those means, but regular mammograms and breast examinations greatly increase the chances of detection and successful treatment.
- Although rare, with only about 1,600 newly diagnosed cases per year, male breast cancer is an important disease. Unfortunately, due to its rarity, it is often not readily diagnosed.
Breast cancer is cancer of the breast tissue. The breast is made up of 15 to 20 sections called lobes that are arranged like the petals of a daisy. In women, each lobe has dozens of tiny bulbs, called lobules, that are capable of producing milk.
Thin tubes or ducts connect the parts of the breast and lead to the nipple in the center of a dark area of skin called the areola. Fatty, connective tissue fills in the spaces. Breast tissue does not include muscles.
How does breast tissue become cancerous?
Like other organs in the body, the breasts are made up of many cells that divide in an orderly, controlled way to make more cells as needed by the body. Sometimes cells divide in an abnormal, uncontrolled way. When that happens, the cells form a growth called a tumor. Tumors can be benign (noncancerous) or malignant (cancerous).
Benign breast lumps usually are caused by changes in the breast's fibrous tissue or by fluid-filled sacs known as cysts. Benign lumps may be removed and most often do not return. With benign lumps, the abnormal cells do not spread to other parts of the body. Benign breast lumps are not life threatening.
Malignant tumors are cancerous. The tumor's cells are abnormal and can spread to healthy cells, damaging and destroying tissues and organs. Cancerous cells also can enter the bloodstream or lymphatic system, causing tumors in other organs.
Please use the following links to access comprehensive breast cancer information provided by the National Cancer Institute from its PDQ® Database.
Learn more about breast cancer...
Learn more about male breast cancer...
Learn more about breast cancer and pregnancy...