Breast Cancer Health Center

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The following stages are used for breast cancer:

Stage 0 (carcinoma in situ)

There are 2 types of breast carcinoma in situ:

• Ductal carcinoma in situ (DCIS) is a noninvasive condition in which abnormalcells are found in the lining of a breastduct. 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, although it is not known at this time how to predict which lesions will become invasive.
• Lobular carcinoma in situ (LCIS) is a condition in which abnormalcells are found in the lobules of the breast. This condition seldom becomes invasive cancer; however, having lobular carcinoma in situ in one breast increases the risk of developing breast cancer in either breast.

Pea, peanut, walnut, and lime show tumor sizes.

Stage I

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

Stage II

Stage II is divided into stages IIA and IIB.

• In stage IIA:
  • no tumor is found in the breast, but cancer is found in the axillary lymph nodes (lymph nodes under the arm); or
  • the tumor is 2 centimeters or smaller and has spread to the axillary lymph nodes; or
  • the tumor is larger than 2 centimeters but not larger than 5 centimeters and has not spread to the axillary lymph nodes.
• In stage IIB, the tumor is either:
  • larger than 2 centimeters but not larger than 5 centimeters and has spread to the axillary lymph nodes; or
  • larger than 5 centimeters but has not spread to the axillary lymph nodes.

Stage IIIA

In stage IIIA:

• no tumor is found in the breast. Cancer is found in axillary lymph nodes that are attached to each other or to other structures, or cancer may be found in lymph nodes near the breastbone; or
• the tumor is 2 centimeters or smaller. Cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone; or
• the tumor is larger than 2 centimeters but not larger than 5 centimeters. Cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone; or
• the tumor is larger than 5 centimeters. Cancer has spread to axillary lymph nodes that may be attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone.