What is (are) Breast Cancer ?
Key Points
                    - Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.    - Breast cancer is the second leading cause of death from cancer in American women.    -  Different factors increase or decrease the risk of breast cancer.
                
                
                    Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
                    The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can produce milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts.     Each breast also contains blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. Lymph vessels lead to organs called lymph nodes. Lymph nodes are small bean-shaped structures that are found throughout the body. They filter substances in lymph and help fight infection and disease. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.   See the following PDQ summaries for more information about breast cancer:         -  Breast Cancer Prevention     -  Breast Cancer Treatment     -  Genetics of Breast and Gynecologic Cancers
                
                
                    Breast cancer is the second leading cause of death from cancer in American women.
                    Women in the United States get breast cancer more than any other type of cancer except for skin cancer. Breast cancer is second only to lung cancer as a cause of cancer death in women.    Breast cancer occurs more often in white women than in black women. However, black women are more likely than white women to die from the disease.   Breast cancer occurs in men also, but the number of cases is small.