There are 4 categories for describing the local extent of a prostate tumour, ranging from T1 to T4. Most of these have subcategories as well.
Your doctor can’t feel the tumor or see it with imaging such as trans-rectal ultrasound.
T1a: Cancer is found incidentally (by accident) during a transurethral resection of the prostate (TURP) that was done for benign prostatic hyperplasia (BPH). Cancer is in no more than 5% of the tissue removed
T1b: Cancer is found during a TURP but is in more than 5% of the tissue removed
T1c: Cancer is found by needle biopsy that was done because of an increased PSA
Your doctor can feel the cancer with a digital rectal exam (DRE) or see it with imaging such as trans-rectal ultrasound, but it still appears to be confined to the prostate gland.
T2a: The cancer is in one half or less of only one side (left or right) of your prostate
T2b: The cancer is in more than half of only one side (left or right) of your prostate
T2c: The cancer is in both sides of your prostate
The cancer has grown outside your prostate and may have grown into the seminal vesicles
T3a: The cancer extends outside the prostate but not to the seminal vesicles
T3b: The cancer has spread to the seminal vesicles
The cancer has grown into tissues next to your prostate (other than the seminal vesicles), such as the urethral sphincter, the rectum, the bladder, and/or the wall of the pelvis.
N categories describe whether the cancer has spread to nearby (regional) lymph nodes.
Nearby lymph nodes were not assessed.
The cancer has not spread to any nearby lymph nodes.
The cancer has spread to one or more nearby lymph nodes.
M categories describe whether the cancer has spread to distant parts of the body. The most common sites of prostate cancer spread are to the bones and to distant lymph nodes, although it can also spread to other organs, such as the lungs and liver.
The cancer has not spread past nearby lymph nodes.
The cancer has spread beyond the nearby lymph nodes.
The cancer has spread to distant (outside of the pelvis) lymph nodes.
The cancer has spread to the bones.
The cancer has spread to other organs such as lungs, liver, or brain (with or without spread to the bones).