Breast diseases can be classified either with disorders of the integuement, or disorders of the reproductive system. A majority of breast diseases are noncancerous.
A breast neoplasm is an abnormal mass of tissue in the breast as a result of neoplasia. A breast neoplasm may be benign, as in fibroadenoma, or it may be malignant, in which case it is termed breast cancer. Either case commonly presents as a breast lump. Approximately 7% of breast lumps are fibroadenomas and 10% are breast cancer, the rest being other benign conditions or no disease. Phyllodes tumor is a fibroepithelial tumor which can either benign, broderline or malignant.
Malignant neoplasms (breast cancer)
Among women worldwide, breast cancer is the most common cause of cancer death. Malignant breast neoplasm is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas. The size, stage, rate of growth, and other characteristics of the tumor determine the kinds of treatment. Treatment may include surgery, drugs, radiation and/or immunotherapy. Surgical removal of the tumor provides the single largest benefit, with surgery alone being capable of producing a cure in many cases. To somewhat increase the likelihood of long-term disease-free survival, several chemotherapy regimens are commonly given in addition to surgery. Most forms of chemotherapy kill cells that are dividing rapidly anywhere in the body, and as a result cause temporary hair loss and digestive disturbances. Radiation may be added to kill any cancer cells in the breast that were missed by the surgery, which usually extends survival somewhat, although radiation exposure to the heart may cause heart failure in the future. Some breast cancers are sensitive to hormones such as estrogen and/or progesterone, which makes it possible to treat them by blocking the effects of these hormones.
Prognosis and survival rate varies greatly depending on cancer type and staging. With best treatment and dependent on staging, 5-year relative survival varies from 98% to 23, with an overall survival rate of 85%.
Worldwide, breast cancer comprises 22.9% of all non-melanoma skin cancers in women. In 2008, breast cancer caused 458,503 deaths worldwide. Breast cancer is more than 100 times more common in women than breast cancer in men, although males tend to have poorer outcomes due to delays in diagnosis.