The Potential Impact of Reproducibility of Gleason Grading in Men With Early Stage Prostate Cancer Managed by Active Surveillance: A Multi-Institutional Study

Conclusions The reproducibility of grading classic Gleason patterns is high. However, variability in grading occurred when distinguishing between tangentially sectioned pattern 3 glands and the poorly formed gland subset of pattern 4. Developing universally accepted histological and/or molecular criteria to distinguish these patterns and subsequently characterizing their natural history would be useful when treating patients on active surveillance.