A Gleason score—on a scale of 2 to 10—is a way of predicting how quickly prostate cancer will grow and how likely it is to spread.

The higher the Gleason score, the more likely it is that the prostate cancer will grow rapidly and spread (metastasize) to other parts of the body.

• A Gleason score of 2 to 6 means the cancer cells look a lot like normal prostate cells. These cancer cells usually grow slowly.
• A Gleason score of 7 means the cancer cells look different from normal cells. These cells are more likely to grow and spread.
• A Gleason score of 8 to 10 means the cancer cells look very different from normal cells. These cells are very likely to grow rapidly and spread to other parts of the body.