TNM staging systemTNM staging system refers to the American Joint Committee on Cancer’s (AJCC) system for determining breast cancer stages. The AJCC developed this system to standardize the way breast cancer stages were assigned so that communication among doctors would be clear. If there were different ways to stage breast cancer, then there would be the potential for confusion between the doctors. TNM stages can refer to the clinical stage, which is when the stage describes the tumor based on testing – prior to surgery. The pathological stage refers to after the surgery has occurred, and measurements are made on the actual tumor and or lymph nodes. On this site, the stages refer to the pathological stage, or after the surgery.
Click here to learn how TNM staging system is different from stage grouping.
T = Tumor size
N = Degree of lymph node involvement (N for Node)
M = Whether the cancer has spread to other parts of the body (M for metastasis which means spread)
A letter or a number follows each of the letters in the TNM stages. See the chart below. Look across the top for the number that will go with the letter that is on the left hand side.
For example, a stage that is: Tis N0 M0 means that:
Tumor = in situ N = no involvement M = no spread Another example: T2 N1 M0 means that:
Tumor = Smaller than 5 cm but larger than 2 cm N = 1 to 3 nodes under the arm have cancer cells in them M = no spread One more example: T1 N3 M1:Tumor = Smaller than 2 cm N = Could be more than 10 nodes with cancer in them, or the nodes at the collar bone or mammary nodes have cancer in them M = Cancer has been detected in another organ (like the lungs, or bones).
|
