Integrating Tertiary Gleason 5 Patterns into Quantitative Gleason Grading in Prostate Biopsies and Prostatectomy Specimens.

Background: Presence of small (tertiary) Gleason 5 pattern is linked to a higher risk of biochemical recurrence in prostate cancer. It is unclear, however, how to integrate small Gleason 5 elements into clinically relevant Gleason grade groups.

Objective: To analyze the prognostic impact of Gleason 5 patterns in prostate cancer and to develop a method for integrating tertiary Gleason 5 patterns into a quantitative Gleason grading system.