Gleason Grading and Scores

Healthier cells have clearly-defined outlines and fairly uniform shapes. The more aggressive the cancer, however, the more irregular and spread out the cells will look.

The pathologist grades two types of cells from your samples: the type of cell that appears most often in all of your samples, and the type that appears the least often. Each type gets a Gleason grade from 1-5, with 1 being the healthiest, 5 being the most cancerous.

The two grades are then added together to form your Gleason score.

What Gleason Scores Mean

Gleason Score	Grade	Meaning
2 to 4	Low	Suggests a cancer that may grow slowly enough to not threaten the patient’s life.
5 to 7	Intermediate	Suggests further analysis may be needed before treatment decisions should be made.
8 to 10	High	Suggests a more serious threat.

Grading is also sometimes referred to as pathological stage (which just means 'the stage determined by a pathologist examining cells under a microscope') as opposed to clinical stage (which means 'the stage determined by a doctor examining a patient in a clinic').

It is very important to get an accurate picture of the cancer's grade, as this is a very important factor in deciding when and how to undergo treatment. Improving on this level of accuracy is a major focus of scientific research.