Causes

• The exact cause of breast cancer is not known. Factors that can increase a woman's risk include heredity, early puberty, late childbearing, obesity, and lifestyle factors such as heavy alcohol consumption and smoking. The biggest risk factor for breast cancer is age -- just growing older. Most breast cancers occur in women over the age of 50, and women over 60 are at the highest risk.
  
  
• A woman's risk for developing breast cancer increases if her mother, sister, daughter, or two or more other close relatives, such as cousins, have a history of breast cancer, especially at a young age. However, 85% of women who develop breast cancer have NO known family history of the disease.
  
  
• Changes in certain genes (BRCA1, BRCA2, and others) make women more susceptible to breast cancer. Genetic testing can determine whether a woman has these abnormal genes.
  
  

Symptoms

The widespread use of screening mammography has increased the number of breast cancers found before they cause any symptoms. But some are still not found early.
The most common sign of breast cancer is a new lump or mass. A lump that is painless, hard, and has uneven edges is more likely to be cancer. But sometimes cancers can be tender, soft, and rounded. So it's important to have anything unusual checked by your doctor.

Other signs of breast cancer include the following:

• A swelling of part of the breast
  
  
• Skin irritation or dimpling
  
  
• Nipple pain or the nipple turning inward
  
  
• Redness or scaliness of the nipple or breast skin
  
  
• A nipple discharge (other than breast milk)
  
  
• A lump in the underarm area
  
  

Stages

Stage	Definition
Stage 0	Cancer cells remain inside the breast duct, without invasion into normal adjacent breast tissue
Stage I	Cancer is 2 centimeters or less and is confined to the breast (lymph nodes are clear)
Stage II	The tumor is over 2 centimeters but no larger than 5 centimeters Or There is spread to the lymph nodes under the arm
Stage III (includes substages IIIA & IIIB)	Also called locally advanced cancer. The tumor is more than 5 centimeters across Or The cancer is extensive in the underarm lymph nodes Or It has spread to other lymph nodes or tissues near the breast
Stage IV	The cancer has spread—or metastasized—to other parts of the body.

Surgery Options

Treatment	Description
Lumpectomy	The malignant tumor and a rim of normal tissue are removed
Quadrantectomy	The malignant tumor and a larger rim of normal tissue are removed
Total or Simple Mastectomy	The whole breast is removed
Modified Radical Mastectomy	The whole breast is removed, along with underarm lymph nodes
Radical Mastectomy	The whole breast, chest muscles, all of the lymph nodes under the arm, and some additional fat and skin are removed
Axillary Dissection	Underarm lymph nodes are removed to determine if cancer has spread
Sentinel Lymph Node Dissection	Only a few underarm lymph nodes are removed. These are the nodes that filter fluid from the affected area of the breast. These nodes are identified using a radioactive substance or blue dye injected near the tumor site within the breast