AJCC TNM Staging
American Joint Committee on Cancer (AJCC) TNM Staging
A staging system is a standard method for the cancer care team to describe how far a cancer has spread. The TNM system is based on 5 key pieces of information:
1. The size and extent of the primary Tumor (T category)
- T1 - The tumor is not detectable with a digital rectal exam (DRE) or imaging but is found in prostate tissue from a biopsy or surgical treatment.
- T1a - Cancer is found in 5% or less of the removal tissue.
- T1b - Cancer is found in more than 5% of the removed tissue.
- T1c - Tumors are found by needle biopsy done for a high PSA.
- T2 - The tumor is detectable with a DRE or imaging but is confined to the prostate.
- T2a - Cancer is in no more than one half of one side of the prostate.
- T2b - Cancer is in more than half of one side of the prostate.
- T2c - Cancer is in both sides of the prostate.
- T3 - Cancer has grown outside the prostate and may have grown into the seminal vesicles.
- T3a - Cancer has spread outside the prostate but not to the seminal vesicles.
- T3b - Cancer has spread to the seminal vesicles.
- T4 - Cancer has grown into other nearby tissues, such as the urethral sphincter, rectum, bladder or wall of the pelvis.
2. Whether the cancer has spread to nearby lymph Nodes (N Category)
- NX - The lymph nodes have not been assessed for cancer.
- N0 - There is no cancer in nearby lymph nodes.
- N1 - Cancer has spread to nearby lymph nodes.
3. The absense or presence of cancer outside the prostate, or Metastasis (M Category)
- MX - It is unknown if cancer has spread to distant sites.
- M0 - The cancer has not spread to distant sites.
- M1 - Cancer has spread to distant sites.
- M1a - Cancer has spread to distant lymph nodes.
- M1b - Cancer has spread to bones.
- M1c - Cancer has spread to distant organs.
4. The PSA level at the time of diagnosis.
Prostate-specific antigen, or PSA, is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in a man's blood. PSA is present in small quantities in the serum of men with healthy prostates, but is often elevated in the presence of prostate cancer or other prostate disorders.
Taken together, this information is used to determine the overall staging for a patient's prostate cancer. The stage is usually expressed in Roman numerals from I (the least advanced) to IV (the most advanced). The AJCC TNM staging system is the most widely used system for prostate cancer and is very important for treatment planning. This information is summarized in the table below.
There are two types of staging for prostate cancer, the first is the clinical stage, which is determined based on the results of a physical exam (including DRE), lab tests, prostate biopsy and imaging tests. The second type of staging is the pathologic stage, which incorporates information gathered during an examination of prostate tissue removed during surgery. Pathologic staging is likely to be more accurate than clinical staging, as it allows for assessment of the prostate tissue. If you have not undergone surgery, your doctor will use the clinical staging method to assess your cancer risk. For patients who have undergone a surgical resection of the prostate, your doctor will use the pathologic staging method and will incorporate information obtained from analysis of your prostate tissue into your diagnosis. This is one possible advantage of having surgery (radical prostatectomy) as opposed to radiation therapy or active surveillance.