In order for a doctor to determine prostate cancer staging, a number of tests (bone scan, CT or CAT scan, MRI, or a ProstaScint™ scan) may be ordered to see if the cancer looks like it is:
- Confined only to the prostate (called localized prostate cancer)
- Spreading outside the prostate (called advanced prostate cancer)
Prostate cancer staging (also called the clinical stage) is based on the results of all of a man’s tests, physical exams, and biopsy.
Based upon these tests, the doctor is really providing an estimate of the extent of the prostate cancer.
If a man has surgery, a pathological stage can usually be more accurately determined based on the gland and tissue that is removed. That is the reason why a man’s Gleason score may be higher after surgery.
The TNM staging system
The TNM staging system is the most commonly used system for determining prostate cancer stages.
With the TNM system:
- The “T” stands for the local extent of the primary tumor.
- The “N” represents the presence of metastases (the spread of cancer) to nearby lymph nodes.
- The “M” represents the presence of “distant” metastases to other parts of the body (this means the cancer has traveled in the bloodstream to bony areas, usually the pelvis, ribs, or long bones with prostate cancer).
Below is a simple table that lists all the categories and tells you more about what each one means.
Prostate cancer staging table
T1: The tumor cannot be felt (is not palpable) during a digital rectal exam or be seen with imaging tests.
T1a: Tumor was discovered unintentionally (called incidentally) in tissue removed for other reasons and 5% or less of the tissue removed is cancerous.
T1b: Tumor was discovered incidentally and more than 5% of the tissue removed is cancerous.
T1c: Tumor was found by a needle biopsy that was performed because of a high PSA.
T2: Tumor appears to be only inside the prostate gland.
T2a: There is cancer in one half (or less) of just one side of the prostate (called one lobe).
T2b: There is cancer in more than half of only one side of the prostate.
T2c: There is cancer in both sides of the prostate.
T3: Cancer extends outside of the prostate and may involve the seminal vesicles.
T3a: Cancer has grown beyond the wall of the prostate (called extracapsular extension) on one or both sides but not to the seminal vesicles.
T3b: Cancer has invaded the seminal vesicles.
T4: Cancer has invaded other areas (other than the seminal vesicles) near the prostate, such as the bladder, rectum, and/or the pelvis wall.
NX: Nearby lymph nodes were not assessed.
N0: Cancer has not spread to any lymph nodes.
N1: Cancer has spread to one or more nearby lymph nodes in the pelvis (called regional lymph nodes).
M0: Cancer has not spread beyond the regional lymph nodes.
M1: Cancer has spread beyond the regional lymph nodes.
M1a: Cancer has spread to distant lymph nodes (outside of the pelvis).
M1b: Cancer has spread to the bones.
M1c: Cancer has spread to other organs, such as the lungs, the liver, or the brain (and may or may not be in the bones).
The American Cancer Society. Prostate Cancer. http://www.cancer.org. Accessed March 17, 2015.
American Urological Association. The Management of Localized Prostate Cancer. http://www.auanet.org. Accessed September 1, 2008.
Walsh PC. Guide to Surviving Prostate Cancer. New York, NY: Time Warner Book Group; 2001.