Prostate cancer is when the cells that make up the prostate gland become abnormal. These cells, when looked at under the microscope look different from normal prostate cells. The usual way of assessing how abnormal the cells are is a system called the Gleason grading system. Biopsies taken from the prostate are looked at under the microscope by specialist doctors, and given a score.
Gleason grading system
The Gleason grading system gives 2 scores for each set of biopsies. Each score is out of 5. It is unusual to have a score of 1 or 2. A score of 3 is the commonest. A higher score means that the cancer is more likely to cause problems by spreading outside the prostate into the surrounding tissues (local advancement), or spread to the bones, or other parts of the body (metastatic disease). A common score is Gleason 3 +3. The largest area is given first – so if your score is 3+4 , this means that you have more of the Gleason 3 pattern than the Gleason 4 pattern.
| Gleason Grade | Cancerous Tissue Pattern |
|---|---|
| 1 | Closely Packed, well defined glands within the prostate |
| 2 | Less uniformly shaped glands |
| 3 | Irregular glands of variable size |
| 4 | A mass of fused glands |
| 5 | Few, or no, visible glands; very little difference between them |
Staging of prostate cancer
The stage of prostate cancer is the way that doctors describe whether the prostate cancer is still contained in the prostate, or how far it has spread. There are three parts to the current staging, known as T (which stand for tumour), N (which stand for nodes) and M (which stands for metastases).
The T stage shows how much of the prostate the cancer occupies. The N stage indicates whether the cancer has spread to the lymph glands (also called lymph nodes) or not. The M stage indicates whether the cancer has spread, or metastasised to anywhere else in the body.
UCC TNM Staging of prostate cancer
| Disease stage | Type of tumour |
|---|---|
| 1 (T1) | Small tumour confined to prostate. Usually not detected by DRE or PSA rise |
| 2 (T2) | Tumour confined to prostate but can be felt during DRE. A small number of these patients have metastases |
| 3 (T3) | Tumour has spread out of the prostate into the surrounding tissue |
| 4 (T4) | Metastases have spread to the bladder and beyond |
