What Is The Gleason Scale?
The Gleason Scale (also referred to as the “Gleason Score” and “Gleason Grading System”), is a system which helps men with prostate cancer to, in conjunction with their specialist or medical practitioner, evaluate their prognosis and potential outcome. It is not the only parameter taken into consideration; however, it is a major factor, given its assignation of a numerical score. It may be used as a predictive tool for outcome, as well as a guide to choosing one or more appropriate therapies. It is based on the appearance – more specifically, the microscopic appearance, usually based on tissue biopsy, of the appearance of the prostate cancer. As a rule within this grading system, a prostate cancer with a number higher up on the Gleason Scale is considered to be more aggressive, with a poorer prognosis.
What Is The Process? In almost all cases, a specialist (they often work together), such as a radiologist or urologist, removes a biopsy from the prostate tissue; this is done with hollow needles, administered through the rectum. Slides are then prepared, using the tissue sample, and are viewed under a microscope. If the prostate is removed during surgery, another specialist (a pathologist) slices the prostate open for a final examination.
Understanding Grading and Scoring
A pathologist will assign a grade to the tumor pattern most commonly found in the sample; and another grade the tumor pattern which occurs with the second-most frequency. These two grades are added, and their sum is used to determine the patient’s Gleason Score. As an example: If the most common pattern found in the tumor was graded a “3″, and the second-most frequently found tumor pattern was graded a “4″, the Gleason Score would be the sum of these two numbers, a “7″. To clarify, the “Gleason Grade” means the “Gleason Pattern”; whereas, the “Gleason Score” is the sum of the two most frequently found tumor patterns within a tissue biopsy.
Features of Gleason Patterns
- Pattern 1: Even if there is cancer in the prostate, the tissue still appears normal, with closely arranged, correctly-formed and small glands
- Pattern 2: There are correctly-formed glands, however, they are bigger than normal and there is a greater amount of tissue between them
- Pattern 3: The glands can still be recognized; however, the cells are darker in color – and at higher levels of microscopic magnification, some of the cells have escaped the glands and have started to invade nearby tissue
- Pattern 4: There are very few recognizable glands remaining in the tissue; a large number of cells have invaded nearby tissue
- Pattern 5: There are no recognizable glands; often, only sheets of cells are found in the nearby tissue
Hopefully this summary of the Gleason Scale has helped you to understand what the numbers mean.