Breast Cancer Stages
Stage I
Cancer that is no bigger than 2 centimeters (about 1 inch) and has not spread outside the breast.
Stage II
Stage II breast cancer means one of the following: cancer is no larger than 2 centimeters but has spread to the lymph nodes in the armpit (the axillary lymph nodes); cancer is between 2 and 5 centimeters (from 1 to 2 inches) and may have spread to the lymph nodes in the armpit; cancer is larger than 5 centimeters (larger than 2 inches) but has not spread to the lymph nodes in the armpit.
Stage III
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. 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.
Stage IIIA
Stage IIIA breast cancer is defined by either of the following: (1) the cancer is smaller than 5 centimeters and has spread to the lymph nodes under the arm, which have grown into each other or into other structures and are attached to them; (2) the cancer is larger than 5 centimeters and has spread to the lymph nodes under the arm.
Stage IIIB
Stage IIIB breast cancer is defined by either of the following: (1) the cancer has spread to tissues near the breast (skin, chest wall, including the ribs and the muscles in the chest); (2) the cancer has spread to lymph nodes inside the chest wall along the breast bone.
Stage IV
Cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain; or cancer has spread locally to the skin and lymph nodes inside the neck near the collarbone.