What is a Gleason Score for Prostate Cancer?
When men have a prostate biopsy to determine whether they have prostate cancer and the extent of the cancer, they are given the results as a prostate cancer Gleason score. While the Gleason score is the most common and useful measure of the severity of your prostate cancer, many patients are confused about exactly what their Gleason score means.
Your Gleason score, named after pathologist Donald Gleason, M.D., can seem a bit like creative accounting. That’s because your Gleason score is actually based on two Gleason grades that are added together.
Gleason grades go from 1 (low) to 5 (high). When a pathologist looks at your prostate tissue biopsy, he will give a primary grade to the area where the cancer is most prominent, and a secondary grade to the next most prominent site. Those grades are added to come up with a Gleason score of 2 to 10.
Interpreting Your Gleason Score
Just like golf, the lower the score the better. However, because there have been great strides in staining techniques since the Gleason grading scale was first introduced in the 1960s, a Gleason score of 6 is now the lowest score we see. To many men, 6 is a scary number because it sounds so high on a scale of 1 to 10. In reality, though, it’s the lowest grade that is currently diagnosed. So talk with your physician before worrying too much.
That being said: within your score, there’s room for interpretation. For example, is a 3+4 the same as a 4+3? They’re both a Gleason score 7, right? Not really.
In general, you want a low primary score. So a 3+4 is a more encouraging Gleason score than a 4+3, but neither one provides complete information on its own. In recent years, additional tests, called biomarkers, have been developed as well as advanced biopsies, such as the 3D biopsy that map the entire prostate, that can be used in conjunction with the Gleason score to form the basis of a customized treatment recommendation.