After the level of aggressiveness of your prostate cancer is estimated (see Gleason Score), the next step, called staging, estimates if or how far the cancer has spread. The older ABCD system of staging prostate tumors has largely been replaced by the TNM (Tumor, Nodes, Metastases) system, which gauges the severity of cancer on an escalating scale.
These three letters are followed by a number and perhaps another letter in small type. The numbers range from 0 to 4 and represent the extent of the tumor. The small letters go from a to c and indicate some subtype of information, as described on the chart below.
Tumor is microscopic and confined to prostate but is undetectable by a digital rectal exam (DRE) or by ultrasound. Usually discovered by PSA tests or biopsies.
Tumor is confined to prostate and can be detected by DRE or ultrasound.
Stage T3 or T4
In stage T3, the cancer has spread to tissue adjacent to the prostate or to the seminal vesicles. Stage T4 tumors have spread to organs near the prostate, such as the bladder.
Stage N+ or M+
To each of the TNM stages above may be added an N,M, or G.
Cancer has spread to pelvic lymph nodes (N+) or to lymph nodes, organs, or bones distant from the prostate (M+).
The N is for lymph nodes. NX means that the lymph nodes cannot be assessed.
N0 means the lymph nodes are not involved.
N1 is a single lymph node, 2 cm or less.
N2 means metastasis in a single lymph node greater than 2 cm or multiple lymph nodes with sum greater than 2 cm.
N3 indicates lymph with greater than 5 cm metastasis.
M is for metastasis.
MX means that distant metastasis cannot be