Stages of Breast Cancer

There are two types of breast cancer in situ. They are early cancers and include:

• ductal carcinoma in situ (DCIS or intraductal carcinoma)

• lobular carcinoma in situ (LCIS)

• this stage may also be called:

  • breast cancer in situ

  • carcinoma in situ

  • stage 0 breast cancer

Paget disease of the nipple is also Stage 0.

Stage I is subdivided into stages IA and IB:

• Stage IA: The tumor is 2 centimeters (about 3/4 inch) or less across, and cancer is not found in any lymph nodes or distant sites. 

• Stage IB: The cancer is 2 centimeters (about 3/4 inch) or less across (or no tumor is found) and very small amounts have spread to the axillary lymph node (lymph nodes under the arm), but not to distant sites. 

Stage II is subdivided into stages IIA and IIB (there is no spread to distant sites in Stage II):

• Stage IIA is defined by any of the following:

  • The tumor is 2 centimeters (about 3/4 inch) or less across, or not found, but cancer is found in 1 to 3 axillary lymph nodes (lymph nodes under the arm). or

  • The cancer is no larger than 2 centimeters (about 3/4 inch) or not found, but has spread in very small amounts to the internal mammary lymph nodes on sentinel lymph node biopsy. or

  • The tumor is 2 centimeters (about 3/4 inch) or less, or not found, has spread to 1 to 3 axillary lymph nodes, and has spread to the internal mammary lymph nodes on sentinel lymph node biopsy. or

  • The cancer is between 2 and 5 centimeters (from 3/4 to 2 inches), but has not spread to any lymph nodes.

• Stage IIB is defined by either of the following:

  • The cancer is between 2 and 5 centimeters (from 3/4 to 2 inches) and has spread to the axillary lymph nodes and/or very small amounts of cancer are found in the internal mammary lymph nodes on sentinel lymph node biopsy. or

  • The cancer is larger than 5 centimeters (larger than 2 inches), but has not spread to any lymph nodes, the chest wall, or the skin.

Stage III is subdivided into stages IIIA, IIIB, and IIIC (there is no spread to distant sites in Stage III).

• Stage IIIA is defined by any of the following:

  • The tumor is less than 5 centimeters (2 inches) or cannot be found in the breast, but cancer is found in 4 to 9 axillary lymph nodes, or has enlarged the internal mammary lymph nodes. or

  • The cancer is larger than 5 centimeters and has spread to the lymph nodes under the arm or the internal mammary lymph nodes, but not to the chest wall or skin.

• Stage IIIB is defined by any of the following:

  • The cancer has spread to tissues near the breast (skin or chest wall, including the ribs and the muscles in the chest), but not into any lymph nodes. or

  • The cancer has spread to tissues near the breast and to 1 to 3 axillary lymph nodes and/or very small amounts of cancer are found in the internal mammary lymph nodes on sentinel lymph node biopsy. or

  • The cancer has spread to 4 to 9 axillary lymph nodes, or it has enlarged the internal mammary lymph nodes.

• Stage IIIC can have a tumor of any size and is defined by any of the following:

  • Cancer has spread to lymph nodes under or above the collarbone and near the neck. or

  • The cancer has spread to 10 or more axillary lymph nodes. or

  • Cancer has spread to lymph nodes under the arm and has enlarged the internal mammary lymph nodes. or

  • The cancer has spread to 4 or more axillary lymph nodes and very small amounts of cancer are found in the internal mammary lymph nodes on sentinel node biopsy.

This stage is defined by either of the following:

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

• The tumor has spread to lymph nodes far from the breast.

This is a rare type of cancer in which the breast looks as if it is inflamed because of its red appearance and warmth. Skin may show signs of ridges and wheals or it may have a pitted appearance. It is considered stage IIIB unless it has spread to distant lymph nodes or organs, then it is stage IV.

In this stage, the cancer has come back (recurred) after treatment. It may come back in the breast, in the soft tissues of the chest (the chest wall), or in another part of the body.