What does breast cancer staging mean?

The stage of your breast cancer refers to a combination of pathology information about the extent of your disease, including:

• Diameter of the (invasive) tumor - This refers to how big the tumor is.
• Nodal involvement - This indicates whether the cancer also affects lymph nodes under the arm, and if so, how many nodes it affects.
• Other organ involvement - This refers to whether the cancer is spreading to other organs like the lungs, bones, liver, or brain.

Staging is important because it helps your doctors create an individualized treatment plan for you. Breast cancer stages are divided into two general categories: early and advanced.

Early breast cancer includes:

• Stage 0 Breast Cancer - This is noninvasive breast cancer, or ductal carcinoma in situ (DCIS). Cancer cells are limited to the lining of the ducts and have not spread beyond the duct.
• Stage I (IA/B) Breast Cancer - This stage means that the cancer has spread from the ducts or lobules into the nearby fatty tissue of the breast. The tumor diameter is less than two centimeters and there is no cancer in the lymph nodes.
• Stage II (IIA/B) Breast Cancer- This stage means that the cancer has spread from the ducts or lobules into the nearby fatty tissue of the breast. The tumor diameter is between two and five centimeters. At this stage the cancer may have spread to the nearby lymph nodes.

Advanced stage breast cancer includes:

• Stage III (IIIA/B) Breast Cancer - This stage means that the tumor may be larger than five centimeters and the cancer may or may not have spread to the nodes, or the tumor is smaller than five centimeters, but has spread to several lymph nodes. Stopping the spread of the cancer is a major concern. This breast cancer stage indicates a diagnosis of inflammatory breast cancer, or an aggressive, fast-growing cancer.
• Stage IV/Metastatic Breast Cancer - This stage indicates that the cancer has spread from the breast and lymph nodes to other parts of the body, including the lungs, liver, bones and/or brain.