The Gleason Score
During the biopsy, several cell samples are taken from throughout the prostate. The two most dominant cell patterns found will be given a score. Cells that look more like healthy cells get a lower score, and the more abnormal the cells look under the microscope, the higher the score.
Those scores are added together to get a Gleason Score. The most predominant cell pattern is first in the equation. For example, if the predominant cell sample receives a score of 3 and the secondary sample receives a 5, together, the score would be 8.
- Gleason 6 or lower: The cells look similar to healthy cells (called well-differentiated), and treatment is not likely needed right away.
- Gleason 7: for this score, there is a difference between 3+4=7 and 4+3=7. When the three is first, the predominant cell pattern is slightly more normal than when the predominant pattern is a 4. The doctor may choose to monitor you closely for signs of cancer growth, or treatments may begin.
- Gleason 8, 9, or 10: The cells look very different from healthy cells (called poorly differentiated or undifferentiated), and treatment is likely to start soon.
Prostate Cancer Grades
Another way of determining the likelihood of prostate cancer growing quickly is through a grading system. The higher the grade (and the higher the Gleason score), the more aggressive the cancer is likely to be.
There are five grades for prostate cancer, and they're related to the Gleason score.
Grade 1: Gleason score of 6 or less
Grade 2: Gleason score of 3+4=7
Grade 3: Gleason score of 4+3=7
Grade 4: Gleason score of 8
Grade 5: Gleason score of 9 or 10