| Definition: | | Stage III is divided into stages IIIA and IIIB. In stage IIIA breast cancer, the cancer (1) is smaller than 5 centimeters and has spread to the lymph nodes in the armpit, which have grown into each other or into other structures and are attached to them; or (2) is larger than 5 centimeters and has spread to the lymph nodes in the armpit. In stage IIIB breast cancer, the cancer (1) has spread to tissues near the breast (skin, chest wall, including the ribs and the muscles in the chest); or (2) has spread to lymph nodes inside the chest wall along the breast bone. |