Staging and Risk Inventory
There is a category of low-risk patients who can be treated with a single therapy or can be followed up with active surveillance. In contrast, a doctor will opt for a combination of therapies in high-risk patients. With so much difference in approach between high-risk and low-risk patients, it is important to have consensus about thedefinition of high or low risk regarding prostate cancer.
There are a number of factors that are included in the risk inventory:
The PSA value is present in the blood at the moment there is prostate cancer, the so-called initial PSA value, is associated with the tumor volume, the Gleason score and tumor progression in certain tissues and / whether there are metastases. The higher the PSA value, the greater the risk of a larger tumor, higher Gleason score, higher risk of continued growth and greater chance of metastasis.
The cut-off values of PSA used to classify the risk as low, moderate and elevated are <10ng/ml, 10.1-20 ng/ml and >20 ng/ml, respectively.
Doctors indicate how aggressive a cancer is with a Gleason score. A pathologist determines the Gleason score using a microscope. This grading indicates the malignancy of the tumor: do the tumor cells still look a lot like normal tissue or do they form a chaotic structure with almost no normal-looking cells? In the latter situation, the tumor is more aggressive than when the cancer cells are still growing in an orderly manner. The Gleason score is a point system based on growth habit and runs from 1 to 5. In 1; the cells in the biopsy have an ordered growth pattern. Whereas in 5; there is an disordered growth pattern. The Gleason score is expressed in 2 numbers, for example Gleason 3+4. The first number indicates the most common growth habit and the second number indicates the second most common growth habit. Gleason 4+3 is therefore prognostically worse than Gleason 3+4.
A Gleason score of ≤6 indicates a low risk. With a Gleason of 7 there is a moderately increased risk. A Gleason score ≥8 places a patient in the high-risk group.
The TNM staging system indicates how the growth is in the prostate (T), whether there are metastases in the lymph nodes (N), and whether there are distant metastases (M). The TNM classification is described below:
The PSA value, Gleason score and TNM score all provide information about the staging of prostate cancer. This table provides an overview of the risk groups.
AJCC Prostate Cancer Prognostic Stage Groups
(8th edition, 2017)
NOTE: When either PSA or Grade Group is not available, grouping should be determined by T category and/or either PSA or Grade Group as available.
Reference table: Buyyounouski MK et al. Prostate cancer – major changes in the American Joint Committee on Cancer eighth edition cancer staging manual. CA Cancer J Clin. 2017 May 6;67(3):245-253.