Breast cancer is a disease in which malignant cancer cells invade breast tissue. It can occur in men and women, although it is much more prevalent in women. The staging of cancer best describes the extent of spread throughout the body. It is based on whether the cancer is invasive or non-invasive, the size of the tumor, how many lymph nodes are involved, and if it has spread to other parts of the body, the American Cancer Society states. Breast cancer staging ranges from a Stage 0 to Stage 4.
Stage 0
Stage 0 breast cancer is the most curable stage of cancer. According to Breastcancer.org, in stage 0, there is no evidence of cancer cells or non-cancerous abnormal cells breaking out of the part of the breast in which they started, or of getting through to or invading neighboring normal tissue. Stage 0 may be treated with surgery (removal of the affected duct) and/or radiation.
Stage 1
Stage 1 breast cancer describes breast cancer that has invaded surrounding breast tissue. To be classified as stage 1, there is a tumor that measures up to 2 centimeters and there is no lymph node involvement. Treatment may consist of surgery and radiation.
Stage 2
Stage 2 breast cancer is divided into stage 2A and stage 2B. Stage 2A classifies a breast cancer in which cells are found in the axillary lymph nodes, or is 2cm or smaller and has spread to axillary nodes, or a tumor that measures between 2 and 5 cm that has not spread to lymph nodes. In stage 2B the tumor is larger than 2 but no larger than 5 centimeters and has spread to the axillary lymph nodes, or the tumor is larger than 5 centimeters but has not spread to the axillary lymph nodes, Breastcancer.org reports.
Stage 3
Stage 3 breast cancer is divided into stage 3A, 3B and 3C. In stage 3 the cancer has spread to either the nearby lymph nodes, breastbone, or the chest wall or skin of the breast. This stage of cancer is more invasive and may be treated with surgery, chemotherapy and possibly radiation.
Stage 4
In stage 4 breast cancer there may or may not be axillary lymph node involvement. The cancer has spread to distant organs or to lymph nodes far from the breast with the most common sites of spread being the bone, liver, brain or lung, the American Cancer Society reports.
