Quote:
Gleason score
The samples of tissue from the biopsy are then studied in a laboratory. If cancerous cells are found, they can be studied further to see how quickly the cancer will spread.
This measure is known as the Gleason score. The lower the score, the less likely the cancer will spread.
A Gleason score of 6 or less means the cancer is unlikely to spread.
A Gleason score of 7 means that there is a moderate chance of the cancer spreading.
A Gleason score of 8 or above means there is a significant chance that the cancer will spread.
Source:
http://www.nhs.uk/conditions/Cancer-of-the-prostate/Pages/Diagnosis.aspx
Click through the links in black type, near to the top of the page, for further information.
Chris