Breast Cancer

Breast cancer is the most common cancer occurring in women and the second most common cause of death from cancer in women after lung cancer. In 2004, approximately 217,440 women in the United States will be diagnosed with breast cancer. An estimated 40,580 women with breast cancer will die of the disease this year.

The breast is comprised mainly of fatty tissue. Within this tissue is a network of lobes, which are made up of tiny, tube-like structures that contain milk glands. Tiny ducts connect the glands, lobules, and lobes and carry the milk from the lobes to the nipple, located in the middle of the areola (darker area that surrounds the nipple of the breast). Blood and lymph vessels run throughout the breast; blood nourishes the cells, and the lymph system drains bodily waste products.

About 90% of all breast cancers occur in the ducts or lobes, with almost 75% of all breast cancers beginning in the cells lining the milk ducts. These cancers are called ductal carcinomas. Cancers that begin in the lobules are called lobular carcinoma and are found in both breasts in approximately 30% of cases.

To learn more about breast cancer, click here (PDF file).