Objectives: To evaluate variables that may predict the Gleason score of radical prostatectomy specimens in patients with more than two different Gleason scores in the positive cores of their biopsy specimens.
Methods: We reviewed the pathologic data of 98 patients who had more than two different Gleason scores in 12-site biopsy specimens. We assessed the following biopsy parameters: the greatest Gleason score on the biopsy specimen, the Gleason score of the greatest tumor percentage in the core, the Gleason score of the largest linear cancer length, and the greatest tumor ratio score (Gleason score of the greatest total tumor length of the same Gleason score/total core length of the same Gleason score). We also assessed the concordance in Gleason scores between biopsy specimens and prostatectomy specimens.
Results: The greatest tumor ratio score was associated with the greatest (67%) concordance rate. The concordance of the greatest Gleason score on biopsy specimens was only 49%. When stratified into categories of well-differentiated (Gleason score 6 or less), moderate (Gleason score 7), and poorly differentiated (Gleason score 8 or more), the grade concordance rate of the greatest tumor ratio score was 73%. The grade concordance rate of the Gleason scores of the greatest tumor percentage in the core, Gleason score core with maximal tumor length, and the greatest Gleason score was 64%, 62%, and 57%, respectively.
Conclusions: If biopsy specimen results in more than two different Gleason scores in the positive cores, the greatest tumor ratio score may be the most useful variable with regard to the prediction of the final Gleason score in the radical prostatectomy specimen.