While the Gleason score determines how aggressive the cancer is, staging the tumor allows doctors to see how far the cancer has spread. There are two different staging systems, the TNM staging system and the Whitmore-Jewett staging system.
The TNM staging system:
Tells you about the size of the tumor and where it has spread.
- T1: Indicates that the cancer cannot be felt or seen by the naked eye
- T2: Indicates that cancer is confined to the prostate gland
- T3 to T4: Indicates that the cancer has spread past the prostate gland into surrounding tissues.
If the cancer has spread to the lymph nodes, this will be indicated by an N
- N1: Indicates a small tumor in the lymph node
- N2: Indicates a medium tumor in one node or several small tumors in several lymph nodes
- N3: Indicates a large tumor in one or more lymph nodes
If the cancer has spread past the lymph nodes, it has metastasized and this is represented by an M
- M1a: Indicates cancer has spread just past the nodes
- M1b: Indicates cancer has spread into the bones
- M1c: Indicates cancer has spread to other sites in the body
Whitmore-Jewett staging system:
In this system, the tumor is classified by letters (A to D).
- Stage A: Indicates that the cancer cannot be felt or seen by the naked eye
- Stage B: Indicates that the cancer is not detectable by the presence of a tumour
- Stage C: Indicates that the cancer has spread to surrounding tissues and vesicles of the prostate
- Stage D: Indicates that the cancer has spread to bones and organs throughout the body