The Gleason grading system is used to help evaluate the prognosis of men with prostate cancer using samples from a prostate biopsy. Together with other parameters, it is incorporated into a strategy of prostate cancer staging which predicts prognosis and helps guide therapy. A Gleason score is given to prostate cancer based upon its microscopic appearance. Cancers with a higher Gleason score are more aggressive and have a worse prognosis. Pathological scores range from 2 through 10, with higher number indicating greater risks and higher mortality. The Gleason grading system is used to help evaluate the prognosis of men with prostate cancer using samples from a prostate biopsy. Together with other parameters, it is incorporated into a strategy of prostate cancer staging which predicts prognosis and helps guide therapy. A Gleason score is given to prostate cancer based upon its microscopic appearance. Cancers with a higher Gleason score are more aggressive and have a worse prognosis. Pathological scores range from 2 through 10, with higher number indicating greater risks and higher mortality. A total score is calculated based on how cells look under a microscope, with the first half of the score based on the dominant, or most common cell morphology (scored 1—5), and the second half based on the non-dominant cell pattern with the highest grade (scored 1—5). These two numbers are then combined to produce a total score for the cancer. Most often, a urologist or radiologist will remove a cylindrical sample (biopsy) of prostate tissue through the rectum, using hollow needles, and biomedical scientists in a histology laboratory prepare microscope slides for H&E staining and immunohistochemistry for diagnosis by a pathologist. If the prostate is surgically removed, a pathologist will slice the prostate for a final examination. A pathologist microscopically examines the biopsy specimen for certain 'Gleason' patterns. These Gleason patterns are associated with the following features: