Stage III Breast Cancer

A stage III breast cancer diagnosis indicates that cancerous cells have begun to grow and spread to lymph nodes and nearby muscles. At this stage, the cancer has not yet progressed to other organs in the body. Stage III breast cancer is divided into stage IIIA, stage IIIB and stage IIIC.

Stage IIIA breast cancer is characterized by one of the following:

  • Cancerous cells have progressed to between four and nine lymph nodes, and no tumor is present or only a small tumor is present (less than two centimeters).
  • Small clusters of cancerous cells are present in the lymph nodes with a tumor greater than five centimeters.
  • Cancerous cells are present in up to three lymph nodes near the breastbone or underarm with a tumor greater than five centimeters.

Stage IIIB breast cancer is characterized by having any size tumor present; cancerous cells in the chest wall or breast skin with inflammation or ulcers or diagnosed as inflammatory breast cancer; and cancerous cells in up to nine lymph nodes under the arm but has not spread to other parts of the body.

Stage IIIC breast cancer is characterized by one of the following:

  • Cancerous cells have progressed to 10 or more lymph nodes under the arm with or without a tumor of any size. Cancer may have penetrated the chest wall or breast skin with inflammation or ulcers.
  • Cancerous cells have progressed to the lymph nodes near the collarbone with or without a tumor of any size.
  • Cancerous cells have progressed to the lymph nodes near the breastbone or underarm with or without a tumor of any size.

Several treatment options are available at stage III. Most women will benefit from some combination of two or more treatments.