Cancer Staging

T is used for Tumor Size. In the image (mammogram or ultrasound) of the tumor, the radiologist can make a measurement of the tumor's size. Sometime this is hard to do, depending on the angle of the tumor in relation to the image film, or if the tumor is deep inside the breast. A tumor has indistinct, or irregular outer edges, sometimes called a spiculated shape. They aren't always round, and they can be longer than they are wide. The most accurate way to get the size of a tumor is to surgically remove all of it, and then measure it. Tumor Size is divided into four classes: T-1 is from 0 - 2 centimeters, T-2 is from 2 - 5 cm, T-3 is greater than 5cm, and T-4 is a tumor of any size that has broken through (ulcerated) the skin, or is attached to the chest wall.

N is used for Lymph Node status. Since cancer can travel through your body in your lymph system, it is important to have your lymph nodes that are nearest the tumor tested for cancer and micro-metastasis. There are two ways to check the lymph nodes: by touch, and by surgery. If your lymph nodes are checked by touch, your surgeon will palpate (feel) the skin just above the lymph nodes, and rate them. If the surgeon cannot feel any swollen nodes, the rating is N-0, if the surgeon can feel some swelling and thinks the nodes are negative (not cancerous) the rating is N-1a, and if the nodes are swollen and appear positive (cancerous) the rating is N-1b. If the lymph nodes feel like they are quite swollen and bunched together (rather lumpy), they are rated N-2, or if they are near the collarbone, they are rated N-3. The second way to evaluate lymph nodes is with a sentinel node biopsy.

M is used for metastasis. If a sample of the nodes have been surgically removed and tested, and are clear of cancer, they are rated M-0, but if they have cancer cells or micrometastasis in them, they are rated M-1.


A distinct phase in the course of a disease. Stages of breast cancer are typically defined by the localization or spread of the tumor. In situ, localized, regional or distant spread usually define which stage the cancer is in.

Stage I
The cancer is no bigger than 2 centimeters (about 1 inch) and has not spread outside the breast. This stage is the ideal time to find the cancer. Treatments are most effective at this stage. Also see Stage 1 Breast Cancer.

Stage II
The cancer is not bigger than 2 centimeters, but has spread to the lymph nodes, or the cancer is between 2 and 5 centimeters and may or may not have spread to the lymph nodes. If the cancer is bigger than 5 centimeters, it has not spread to the axillary nodes. Also see Stage II Breast Cancer.

Stage III
(IIIa) The cancer is bigger than 5 centimeters and has spread to the lymph nodes or is smaller than 5 centimeters, but has spread into the lymph nodes and other structures attached to them.

(IIIb) The cancer has spread to tissues near the breast usually the chest wall, including the ribs and muscles in the chest.

Stage IV
The most serious stage where the breast cancer has spread to other organs of the body, most often the bones, lungs, liver or brain.

Karen Moody ...© All rights reserved