Gleason grading system
（重定向自Gleason system）
![Gleason grade Lower grades are associated with small, closely packed glands. Cells spread out and lose glandular architecture as grade increases. Gleason score is calculated from grade as described in the text.](/Images/godic/202501/15/Gleasonscore0137.jpg")
![Gleason Pattern 3. H&E stain.](/Images/godic/202501/15/Gleason_30137.jpg")
![Gleason pattern 4. H&E stain.](/Images/godic/202501/15/Prostate_cancer_with_Gleason_pattern_4_low_mag0138.jpg")
![Gleason pattern 4 (left of image) and Gleason pattern 5 (right of image). H&E stain.](/Images/godic/202501/15/Gleason_4_and_5_intermed_mag0138.jpg")
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.