What does the Gleason score mean?

When diagnosing prostate cancer, a Gleason score is used to determine how aggressive the cancer is. Before understanding what the Gleason score means, one should know how a Urologist comes up with a Gleason score in the first place. To identify the Gleason score, a Urologist will do a prostate biopsy which involves collecting prostate tissue samples. These prostate tissue samples are then sent to a lab to be analyzed by a pathologist. The pathologist will determine the Gleason score which is made up of two numbers: a primary grade and a secondary grade.

The primary grade determines where the cancer is the most prominent and the secondary grade determines where the cancer is next most prominent. The primary grade and the secondary grade will be a number ranging from 1 to 5. These numbers are then added together to come up with a Gleason score that ranges from 6 to 10. The higher the Gleason score, the more aggressive the cancer, and the more likely it is to spread.

Two of the most common Gleason scores that men are given are 7 (3+4) and 7 (4+3). While these numbers do not seem that different from each other, they are actually very different and may mean a different prognosis. What is the difference between a Gleason score of 7 (4+3) and a Gleason score of 7 (3+4)? A Gleason score of 7 (4+3) means that the prostate cancer is slightly more aggressive than the prostate cancer with a Gleason score of 7(3+4). This is because with the Gleason score of 7 (4+3), there is more grade 4 cancer since the first number is the primary grade.

Other possible Gleason scores explained:

·         3+3: All of the cancer cells found in the biopsy look likely to grow slowly.

·         3+4: Most of the cancer cells found in the biopsy look likely to grow slowly. There were some cancer cells that look more likely to grow at a more moderate rate.

·         4+3: Most of the cancer cells found in the biopsy look likely to grow at a moderate rate. There were some cancer cells that look likely to grow slowly.

·         4+4: All of the cancer cells found in the biopsy look likely to grow at a moderately quick rate.

·         4+5: Most of the cancer cells found in the biopsy look likely to grow at a moderately quick rate. There were some cancer cells that are likely to grow more quickly.

·         5+4: Most of the cancer cells found in the biopsy look likely to grow quickly.

·         5+5: All of the cancer cells found in the biopsy look likely to grow quickly.