Cancer staging is a term used to refer to describing the tumor's size and whether or not it has spread beyond the area where it began.

Staging systems are constantly being updated to be able to help doctors plan the best treatment and help give them an idea of the probably outcome of treatment.

Your doctors will describe your cancer using the TNM and number staging systems.


TNM classification

This system gives precise information about the stage that the cancer is in.

T- Tumor

Describes the size of the tumor and whether it has begun to spread. A number is placed beside the T to describe the size and the extent to which it has propagated.

N- Nodes

This is a description of whether the cancer has spread to the lymph nodes. N 0 means there is no spread to lymph nodes, and N 1-3 means that the lymph nodes are affected

M-Metastasis

This describes whether the cancer has spread to another part of the body. The letter M may have a number beside it; for example, M 0 means that there is no metastasis, while M1 indicates metastasis in some part of the body.


Breast-cancer stages

  • Stage 1 the size of the tumor is 20 mm of less and the lymph nodes in the underarm have not bee invaded.
  • Stage 2
    • Stage 2 A: the tumor is smaller than 20 mm, though it has invaded the axillary lymph nodes or is larger than 20 mm and has not invaded the lymph nodes.
    • Stage 2 B: the tumor is smaller than 50mm, though it has invaded the axillary lymph nodes or is larger than 50 mm and the lymph nodes remain intact.
  • Stage 3
    • Stage 3 A: when the tumor is larger than 50 mm and has invaded the axillary lymph nodes or other lymph nodes.
    • Stage 3 B: the cancer has spread to the tissue surrounding the breast
    • Stage 3 C: when the cancer has invaded the axillary and clavicular lymph nodes.
  • Stage 4: when the cancer has spread to other parts of the body such as bones, lungs, or liver. This stage is called metastatic breast cancer.