Published: Aug. 25, 2011
Updated: Feb. 9, 2012
Prostate cancer is divided into stages to indicate how advanced the cancer is.
While there are several methods to grade prostate cancer, Duke Cancer Institute physicians use the Gleason scale, a system of grading prostate cancer tissue based on how it looks under a microscope.
Gleason scores range from 2 to 10 and indicate how likely it is that a tumor will spread.
A low Gleason score means the cancer tissue is similar to normal prostate tissue and the tumor is less likely to spread; a high Gleason score means the cancer tissue is very different from normal and the tumor is more likely to spread.
Most men with early-stage prostate cancer have a Gleason score of 6 or 7.
Learn more about prostate cancer: