The Gleason score is a score assigned to prostate cancer to help doctors devise an appropriate treatment plan and provide a generalized prognosis, according to the American Society of Clinical Oncology. Lower scores indicate better prognoses and the less likely cancer is to spread beyond the prostate.
The Gleason system is the most common grading system used by oncologists, according to the American Society of Clinical Oncology. It is used along with staging to customize treatment that best suits an individual’s condition. The lowest score on the Gleason scale is a six, which indicates a low-grade cancer that grows slowly. A Gleason score of seven indicates a medium-grade prostate cancer, while scores of eight through ten are indicative of high-grade prostate cancer.
Biopsied prostate cells are used to determine the Gleason score for prostate cancer, advises the American Society of Clinical Oncology. In the lab, a pathologist examines the cancer cells and how they are arranged in order to assign a score. Those that are similar to healthy prostate cells get low scores, while the cells that are less similar to healthy cells are assigned higher scores. A high Gleason score may indicate the need for more advanced treatment, while a low score may indicate prostate cancer that is slow growing and requires only active surveillance for the time being.