Breast cancer is categorized, based on the size and location of the tumor into 5 stages (O – IV).

Stage 0

Represents non-invasive types of breast cancers (Ductal Carcinoma In Situ and Lobular Carcinoma In Situ). The types are considered non-invasive because the malignant cells are contained in one area and have not metastasized (moved) to the lymph nodes, other areas of the breast, or developed to deeper tissues in the breast area. The American Cancer Society predicts 54,010 new cases of these types of breast cancers in 2010.

The first and most commonly known type, Ductal Carcinoma In Situ (DCIS), occurs in about 80% of women. DCIS occurs when the cells are confined to the linings of the ducts (i.e., where the milk is produced) and have not spread through the walls of the surrounding breast tissues. Women with DCIS are at a greater risk for developing invasive breast cancer in the future.

The second type of Stage 0 breast cancer, Lobular Carcinoma In Situ (LCIS), occurs in 12% of cases. LCIS is when the cells are confined to the lobular linings (i.e., tubes where the milk passes to the nipple) of the breast area (Onconolink, 2003). Many professionals do not consider LCIS to be a real cancer, although women with this condition are at risk of developing invasive breast cancers in the same or opposite breast in the future (ACS, 2010). Women with LCIS are expected to make a complete recovery and have the best prognosis for an excellent (100%) 5 year survival rate.

Stage I is considered the earliest form of a true cancer tumor. Patients diagnosed at this stage also have an excellent (100) 5-year survival rate because the tumors are relatively small, less than 2 cm or about 1 inch in size, and have not spread beyond the breast region (ACS, 2010).

Stage II tumors are invasive masses characterized by varying sizes and regions and are considered an early stage tumor, if the size is less than 2 cm.

Stage IIA tumors have several existing conditions. First, the tumor is less than 2 cm across and is confined to the breast area. Secondly, the tumor ranges in size from 2-5 cm and has not spread to the lymph nodes. Finally, the tumor ranges in size from 2-5 cm, has spread to the lymph nodes, but has not spread from the underarm area.

Stage IIB tumors are at least 5 cm, but have not metastasized beyond the breast. The immediate prognosis for this stage is favorable, with a 5 year survival rate of 86% for Stage IIA, but a lesser survival rate for Stage IIB (ACS, 2010).

Stage III is considered an advanced stage of the disease. During this stage, the cancer has progressed to 5 cm in size and has spread to the lymph nodes. In many cases, the cancer also has spread to the breastbone or other areas near the breast. Additionally, the cancer can be found in the chest walls, mammary glands, or seen topically on the skin of the breast. A patient diagnosed in this stage has a good prognosis for recovery, and a 57% survival rate for 5 years (ACS, 2010).

Stage IV occurs when the disease metastasizes to distant areas of the body. At this stage, the disease invades the local areas of the breast skin and lymph nodes, in addition to distant tissues and organs outside of the breast area such as the bones, lungs, liver, and brain. Few patients at this stage are given a favorable prognosis for survival; in fact only 20% of the women survive 5 years or more (ACS, 2010).