Hitaishini

Breast cancer is cancer that affects the breast. The vast majority of breast cancer occurs in women, although men can develop breast cancer too.

'Cancer' is the name for a group of diseases in which the body's cells are changed in appearance and function. Such abnormal cells can grow out of control and form a mass or 'tumor.' When abnormal cells originate in the breast tissue, the mass is called a breast tumor.

A breast tumor is considered benign if it is limited to a few cell layers and does not invade surrounding tissues or organs. Yet if the tumor spreads to surrounding tissues or organs, it is considered malignant, or cancerous. Carcinoma is the term used to describe most common cancers that arise from epithelial (surface or lining) tissues. By contrast, sarcoma is the term used to define tumors that arise from bone, muscle, fat, or connective tissues.
	Inflammatory Breast Cancer Left Breast	Inflammatory Breast Cancer Right Breast

The breasts are, in essence, a collection of fatty tissues and glands that have been adapted to secrete milk after a woman gives birth. The glands that produce milk are called lobules and the tubes that connect them to the nipples are called ducts. Correspondingly, carcinoma of the breast develops when malignant changes occur in the cells that line the lobules or, more commonly, the ducts.

There are two major types of breast cancer:

lobular carcinoma, and
ductal carcinoma.

They can be either invasive (spreading) or noninvasive (generally known as 'in situ' - confined to the original site). The majority of breast cancers (70% - 80%) arise from the ducts, which make up the bulk of breast tissue. Since lobular and ductal cells are found in the glandular tissues of the upper, central, and outer regions of the breast, this is where most breast cancers occur. Breast tumors rarely arise in the fatty or nonglandular tissues. Such tumors, when they appear, are usually sarcomas.

Cells from the tumor may break away, travel, and grow within other parts of the body. This process is known as metastasis. Breast cancer often metastasizes to sites such as the lung, bone, liver, and brain. If breast cancer is detected at an early stage - for example, before metastasis - it usually can be cured; however, as the disease progresses, the possibility of effective treatment is diminished. Fortunately, though, many breast "lumps" are caused by benign breast diseases that do not spread beyond the breasts and are not life-threatening.