ABSTRACT
OBJECTIVES: We analyse the concordance between Gleason scores on prostate biopsies diagnostic of adenocarcinoma and radical prostatectomy specimens. METHODS: We reviewed the charts of 214 patients who underwent radical prostatectomy between January 1992 and November 2002. We calculated the percentage of correct diagnosis, understaging and overstaging for individual Gleason and for groups with scores between 2-4, 5-6, 7 and 8-10. We performed the statistical analyses of concordance for the groups using the kappa weighted index (< 0.4 low reliability, 0.4-0.75 good reliability; > 0.75 excellent reliability). RESULTS: 41 patients were excluded. The percentages of right diagnosis, understaging and overstaging for the remainder 173 were 32.3%, 44% and 23.7% respectively for individual Gleason scores, and 52.6%, 32.4% and 15% respectively for grouped Gleason scores. Statistical analysis resulted in a kappa weighted index of 0.52, a result which did not vary after excluding patients treated with neoadjuvant hormonal therapy CONCLUSIONS: In our series, the statistical correlation obtained for grouped Gleason scores is good. However, understaging is the biggest problem for prostate biopsies diagnostic of adenocarcinoma when compared with definitive pathologic results on the specimen. Besides, and in opposition, more than 50% of our patients deemed as less differentiated (Gleason score 7 and 8-10) presented lower grades in the specimen. Both limitations should be taken into consideration when therapeutic options are exposed to our patients.
