What is a Gleason Stage and Gleason Score?

Prostate cancer is classified by the pathologist looking at the tissue under a microscope. This classification is according to what's known as a Gleason stage which ranges from 1 to 5 with 5 being the most aggressive and 1 being the least aggressive. When prostate tissue is examined, the most common appearing section of tumor is given a number, such as Gleason 2, and the next most common appearing tumor also given a number, such as 3. In the above case, with the most common tumor cells being 2 and the second most frequent tumor cells being 3, the Gleason score would be a 2+3 = 5. Although the urologist who will be treating you will explain the Score in greater detail, it is a good rule of thumb that a Gleason score of 2 through 6 is associated with a very high percentage of successful treatment. A score of 7 has a lesser chance of successful treatment and a score of 8 to 10 carries a poor chance of success regardless of what type of treatment is performed.