The Gleason score was devised in the 1960s by Don Gleason, a pathologist at the Minneapolis Veterans Administration (VA) Hospital. He recognized that prostate cancer cells organize themselves into discrete patterns as they change from normal cells to cancer cells. The higher the score, the most aggressive the cancer. The Gleason score is still considered the ultimate indicator of the potential for prostate cancer to grow and spread.
The lowest Gleason score is 6, which is a low-grade cancer. A medium-grade cancer is a Gleason score of 7 and a high-grade cancer is a Gleason 8, 9 or 10.
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