Stage 3 breast cancer is an advanced cancer. It has spread to the lymph nodes but not to other organs. This stage is divided into three categories–3A, 3B, and 3C–based on tumor size and lymph node involvement.
Any of the following can qualify as a stage 3A cancer, according to the National Cancer Institute:
Either no tumor or a tumor of any size and cancer in four to nine nearby lymph nodes A tumor larger than 5 centimeters across (about 2 inches) and small clusters of breast cancer cells in the lymph nodes A tumor larger than 5 centimeters and cancer in one to three lymph nodes near the breastbone.A stage 3B cancer can be any size. The cancer is in the chest wall or the skin of the breast, which can cause swelling. It has spread to up to nine nearby lymph nodes.
At stage 3C, there may be a tumor of any size, or no tumor, and either:
Cancer in 10 or more lymph nodes under the arm Cancer in the lymph nodes near the collarbone Cancer in the lymph nodes under the arm and near the breastboneStage 3 treatments vary widely. Some people require surgery–either the removal of the entire breast, called a mastectomy, or a breast-conserving surgery called a lumpectomy–and radiation, plus chemotherapy and lymph node removal. Patients may have hormone treatment or targeted cancer therapy.
Other patients may undergo chemo first to shrink the tumor, followed by mastectomy and radiation. Hormone therapy and targeted cancer therapies may be used when appropriate. People with stage 3 breast cancer will usually have surgery to remove at least some of the lymph nodes under the arm and may have radiation to treat lymph nodes near the collarbone and breastbone.