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Patient Education: Diseases Conditions Treatments & Procedures

Breast Cancer

Stages of Breast Cancer

Once your physician has all of the information from your surgery and other tests, your breast cancer will be given a Stage. This information includes details of the size of a tumor, its characteristics, and whether it has spread to the lymph nodes under the arm (axilla) or to more distant areas of the body.

Breast cancer staging is extremely important because it provides information about the risk of the disease coming back (called recurrence) and it guides the choice of treatment to reduce the risk of cancer coming back.

Breast cancers are staged anywhere from 0 to IV
Stage 0: This is called "in situ" cancer. The breast cancer cells have not gone beyond the breast ducts and are considered "pre cancerous" or "non-invasive". Ductal Carcinoma in Situ (DCIS) is an example of Stage 0 breast cancer.

Stage I: The tumor is less than 2 centimeters in diameter and has not spread outside the breast.

Stage II: The tumor is between 2 and 5 centimeters in diameter or has spread to the lymph nodes, or both,

Stage III: The tumor is larger than 5 centimeters in diameter or has spread to other tissues near the breast (such as the skin or chest wall), or has spread to a large amount of lymph nodes.

Stage IV: The tumor can be any size and has spread to other sites outside of the breast such as lung, bone and liver. Stage IV is also known as metastatic disease.

Visit the Breast Care Group at Odette Cancer Centre