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Breast Cancer Treatment (PDQ®): Treatment - Patient Information [NCI] - Stages of Breast Cancer

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When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for breast cancer:

This section describes the stages of breast cancer. The breast cancer stage is based on the results of testing that is done on the tumor and lymph nodes removed during surgery and other tests.

Stage 0 (carcinoma in situ)

There are 3 types of breast carcinoma in situ:

  • Ductal carcinoma in situ (DCIS) is a noninvasive 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. In some cases, DCIS may become invasive cancer and spread to other tissues. At this time, there is no way to know which lesions could become invasive.
    cdr0000734087.jpg
    Ductal carcinoma in situ (DCIS). Abnormal cells are found in the lining of a breast duct.
  • Lobular carcinoma in situ (LCIS) is a condition in which abnormal cells are found in the lobules of the breast. This condition seldom becomes invasive cancer. However, having LCIS in one breast increases the risk of developing breast cancer in either breast.
    cdr0000734077.jpg
    Lobular carcinoma in situ (LCIS). Abnormal cells are found in the lobules of the breast.
  • Paget disease of the nipple is a condition in which abnormal cells are found in the nipple only.

Stage I

cdr0000732256.jpg
Stage I breast cancer. In stage IA, the tumor is 2 centimeters or smaller and has not spread outside the breast. In stage IB, no tumor is found in the breast or the tumor is 2 centimeters or smaller. Small clusters of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes.

In stage I, cancer has formed. Stage I is divided into stages IA and IB.

  • In stage IA, the tumor is 2 centimeters or smaller. Cancer has not spread outside the breast.
  • In stage IB, small clusters of breast cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes and either:
    • no tumor is found in the breast; or
    • the tumor is 2 centimeters or smaller.

Stage II

Stage II is divided into stages IIA and IIB.

  • In stage IIA:
    • no tumor is found in the breast or the tumor is 2 centimeters or smaller. Cancer (larger than 2 millimeters) is found in 1 to 3 axillary lymph nodes or in the lymph nodes near the breastbone (found during a sentinel lymph node biopsy); or
    • the tumor is larger than 2 centimeters but not larger than 5 centimeters. Cancer has not spread to the lymph nodes.

    cdr0000732257.jpg
    Stage IIA breast cancer. No tumor is found in the breast and cancer is found in 1 to 3 axillary lymph nodes or lymph nodes near the breastbone (left panel); OR the tumor is 2 centimeters or smaller and cancer is found in 1 to 3 axillary lymph nodes or lymph nodes near the breastbone (middle panel); OR the tumor is larger than 2 centimeters but not larger than 5 centimeters and has not spread to the lymph nodes (right panel).
  • In stage IIB, the tumor is:
    • larger than 2 centimeters but not larger than 5 centimeters. Small clusters of breast cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes; or
    • larger than 2 centimeters but not larger than 5 centimeters. Cancer has spread to 1 to 3 axillary lymph nodes or to the lymph nodes near the breastbone (found during a sentinel lymph node biopsy); or
    • larger than 5 centimeters. Cancer has not spread to the lymph nodes.

    cdr0000732258.jpg
    Stage IIB breast cancer. The tumor is larger than 2 centimeters but not larger than 5 centimeters and small clusters of cancer cells are found in the lymph nodes (left panel); OR the tumor is larger than 2 centimeters but not larger than 5 centimeters and cancer is found in 1 to 3 axillary lymph nodes or lymph nodes near the breastbone (middle panel); OR the tumor is larger than 5 centimeters and has not spread to the lymph nodes (right panel).
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WebMD Public Information from the National Cancer Institute

Last Updated: February 25, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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