Following an initial diagnosis of breast cancer, a woman often feels frightened and overwhelmed; then later as she adjusts, she starts to gather as much information about her condition as possible, both from her medical doctors and from outside sources. In the meantime, the physician will have started the patient on additional tests that will pinpoint the specifics of the woman’s cancer. This important testing will establish what is called her breast cancer stage.

It should be noted that breast cancer is different in each individual and, therefore, the breast cancer stage of each patient’s disease needs to be classified. This is all very confusing to the newly initiated woman and family, but this rating system is vital for detailing each person’s tumor. Then the best possible treatment plan can be designed by her doctors. This process called “staging” is most commonly expressed through a system which uses Roman numerals, capital letters, more capital letters, and numbers (called the AJCC/TNM staging system). After all diagnostic tests are completed, the woman’s breast cancer stage is then assigned.

Under the Roman numerals, the breast cancer stage of 0 means the cancer is confined to the site of origin; I through IV establishes progression, with IV meaning the cancer is the worst and has spread to other parts of the body (called metastasis). As listed in the American Cancer Society’s summary of breast cancer stages, the capital letters following the Roman numerals are A and B and C, further rating the progression of the tumor in severity. The capital letters used next are T and N and M: T is for “tumor” size and location; N stands for lymph “node” involvement; M means “metastasis” and denotes whether the cancer has spread to a distant area of the body. These letters are followed by numbers (usually 1, 2, 3, 4) which detail even more precise rating.

A classification of the breast cancer stages combines the Roman numbers, capital letters and numbers. For example, Stage I: T1, N0, M0 is a tumor of 2 cm. or less, no lymph node involvement, no metastasis. Another example is Stage IIIB: T4, N0-2, M0 where the tumor is enlarged, involves 0 to more lymph nodes, but has no metastasis. The most serious of the breast cancer stages is Stage IV: T0-4, N0-3, M1 where the tumor can be small to large in size, may be in the lymph nodes, and has definitely spread (metastasized) to another area of the body, like the liver, lungs or bones.

For those who like to visualize in a table form, the stages are listed below, using the T, N, M classifications:

Stage O:
Tis, N0, M0 (“is” stands for “in situ”)

Stage I:
T1, N0, M0

Stage IIA:
T0, M1, M0
T1, N1, M0
T2, N0, M0

Stage IIB:
T2, N1, M0
T3, N0, M0

Stage IIIA:
T0, N2, M0
T1, N2, M0
T2, N2, M0
T3, N1, M0
T3, N2, M0

Stage IIIB:
T4, N0-2, M0

Stage IIIC:
T0-4, N3, M0

Stage IV:
T0-4, N0-3, M1