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Stages of breast cancer

Reading your pathology report (Adapted from the National Cancer Institute’s Stages of Breast Cancer)

Early Stage Breast Cancer

Stage 0 (ductal carcinoma in situ)

  • Ductal carcinoma in situ (DCSI) is a noninvasive precancerous condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast.

Stage I

  • The tumor is two centimeters or smaller and has not spread outside the breast.

Stage IIA 

  • No tumor is found in the breast, but cancer is found in the axillary lymph nodes (the lymph nodes under the arm).
  • The tumor is
    • two centimeters or smaller and has spread to the axillary lymph nodes
    • between two centimeters and five centimeters but has not spread to the axillary lymph nodes

Stage IIB

The tumor is:

  • between two centimeters and five centimeters and has spread to the axillary lymph nodes (one to three nodes)
  • larger than five centimeters but has not spread to the axillary lymph nodes

Advanced Breast Cancer

Stage IIIA

  • No tumor is found in the breast, but cancer is found in axillary lymph nodes that are attached to each other or to other structures
  • The tumor is:
    • five centimeters or smaller and has spread to the axillary lymph nodes that are attached to each other or to other structures or four to nine pos. nodes OR
    • larger than five centimeters and has spread to axillary lymph nodes that may or may not be attached to each other or to other structures

Stage IIIB

The cancer may be any size and:

  • has spread to tissue near the breast (the skin or chest wall, including ribs and muscles in the chest) AND
  • may have spread to lymph nodes within the breast or under the arm (any number)

Stage IIIC

  • The cancer has spread to lymph nodes beneath the collarbone and near the neck AND
  • May have spread to lymph nodes within the breast or under the arm and to tissues near the breast

Stage IIIC breast cancer is divided into operable and inoperable stage IIIC.

  • In operable stage IIIC, the cancer: 
    • is found in 10 or more of the lymph nodes under the arm OR
    • is found in lymph nodes beneath the collarbone and near the neck on the same side of the body as the breast cancer OR
    • is found in lymph nodes within the breast itself and in lymph nodes under the arm
  • In inoperable stage IIIC, the cancer has spread to the lymph nodes above the collarbone and near the neck on the same side of the body as the breast with cancer.

Stage IV

  • The cancer has spread to other organs of the body, most often the bones, lungs, liver or brain.