Clinical tumor stage refers to whether or not the tumor can be palpated or felt on exam and whether it may have spread to lymph nodes or other organs. Clinical stage is based on all information available prior to any treatment and designated by the TNM (tumor, node, metastasis) system described below.
TNM
Explanation
T1a
Unsuspected cancer found incidentally during prostate removal (occupying less than 5 percent of prostate).
T1b
Unsuspected cancer found incidentally during prostate removal (occupying more than 5 percent of prostate).
T1c
Cancer that is detected only because of elevated PSA (normal exam).
T2a
Cancer that is felt and occupies 50 percent or less of one side.
T2b
Cancer that is felt and occupies more than 50 percent of one side.
T2c
Cancer that is felt and occupies both sides of the prostate.
T3a
Cancer occupying one side and growing outside of the capsule.
T3b
Cancer occupying both sides and growing outside of the capsule.
T3c
Cancer that has invaded the seminal vesicles.
T4a
Cancer that involves the bladder neck and/or rectum and/or external sphincter.
T4b
Cancer that involves other areas near the prostate.
N0
No cancer detected in the lymph nodes.
N1 (N+)
Cancer spread to one or more lymph nodes measuring less than 2 cm.
N2 (N+)
Cancer spread to one or more lymph nodes measuring 2-5 cm.
N3 (N+)
Cancer spread to one or more lymph nodes measuring more than 5 cm.
M0
Cancer that is confined to the prostate, surrounding tissues and pelvic lymph nodes.
M1 (M+)
Cancer that has spread beyond the pelvic area to bones, lungs, etc.