Once a person is determined to have a malignant tumor or the diagnosis of breast cancer, the healthcare team will determine staging to communicate how far the disease has progressed.

Why is the Breast cancer stage important?

  • Determining the stage helps determine the best way to contain, treat and eliminate the breast cancer.

How is the stage determined?

  • The stage is based on the following factors:
    • The size of the tumor within the breast
    • The number of lymph nodes affected
    • The nearest lymph nodes are found under the arm, known as the axillary area
    • Signs indicating whether or not the breast cancer has invaded other organs within the body


Stage 0

  • The earliest detection of breast cancer development
  • Non invasive
  • No evidence of cancer cells or other abnormal cells have spread to other parts of the breast or other parts of the body
  • Difficult to detect

Stage I

  • The earliest detection of breast cancer development
  • The cancer has not spread to the lymph nodes
  • The cancer has not spread outside the breast
  • The tumor is no more than 2 centimeters in diameter (about the size of a peanut without the shell)
  • Treatment is highly effective and consists typically of surgery and often radiation or a combination of the two

Stage II

  • Slightly more advanced form of breast cancer
  • The tumor is 2 to 5 centimeters in diameter
  • Invasive breast cancer in which a tumor is found in the nearby lymph nodes and not spread to a distant part of the body

Stage III

  • A more advanced form of invasive breast cancer
  • Known as locally or regionally advanced cancer
  • The cancer may have spread to lymph nodes near the breast-those located under the arm or by the collarbone-but not to more distant parts of the body
  • The tumor may also be quite large at this stage, possibly extending to the chest wall or the skin of the breast

Stage IV

  • Stage IV is the most advanced form of breast cancer
  • Stage IV means the cancer has spread (metastasized) elsewhere in the body
  • The affected areas may include the bones, brain, lungs, or liver… more than one part of the body may be involved.


For more information, please visit: http://www.nationalbreastcancer.org/breast-cancer-stages