Breast cancer is a malignant tumor that originates in the breast tissue.
Breast tissue consists primarily of breast lobes and breast ducts. The normal unilateral breast has 15-20 lobes, each of which is made up of many smaller lobules.The follicles at the end of the lobules produce milk.The lobes, lobules, and follicles are connected to each other by ducts.
Anatomy of the female breast The nipple and areola are centrally located on the skin surface of the breast, and the lymph nodes, lobules, lobules, ducts, and other tissue structures within the breast are also shown (in the figure).
Blood vessels and lymphatic vessels are distributed in the breast.The colorless fluid in the lymphatic vessels is lymph fluid. The lymphatic fluid flows between the lymph nodes through the lymphatic vessels.The lymph nodes are shaped like small beans and have the function of filtering lymph fluid, storing white blood cells, fighting infection and preventing disease.There are several groups of lymph nodes distributed near the breast, including axillary lymph nodes, supraclavicular lymph nodes, and chest lymph nodes.
For more information about breast cancer, see the following PDQ summary:
Breast cancer is the second most common type of cancer among women in the United States.
Breast cancer is second only to skin cancer and higher than all other types of cancer among women in the United States. Among deaths due to cancer, breast cancer is the second leading cause of cancer death in American women after lung cancer.However, from 2007 to 2016, the number of deaths from breast cancer in the United States decreased slightly each year.In addition, breast cancer can occur in men, but new cases are rare.
Oncology registry data in China show that the incidence of breast cancer was on an upward trend from 2000-2014, and by 2014, it was approaching the level of developed countries such as Australia.