Should a Gleason score be assigned to a minute focus of carcinoma on prostate biopsy?
The grading system for prostate carcinoma devised by Gleason is a strong prognostic indicator. The primary and secondary patterns are combined to give a tumor score, referred to as Gleason score or sum. Gleason scores on biopsy correlate with the prostatectomy Gleason scores, and in combination with pretreatment serum prostate-specific antigen and digital rectal examination results, predict tumor stage and lymph node status. However, when only a minute focus of tumor is present on biopsy, the Gleason score is assigned by doubling the Gleason pattern. The goal of this study was to determine if a Gleason score assigned to a minimal focus of adenocarcinoma had predictive value. Paired biopsies and prostatectomy specimens from 963 cases of men with clinically localized prostate cancer were examined. Minimal tumor on biopsy was defined as less than 1 mm or 5% involvement of one biopsy core; excluded from this definition were biopsies where two Gleason patterns could be identified and/or tum
