PROSTATIC ADENOCARCINOMA GRADING SYSTEM ACCORDING TO 2016 WORLD HEALTH ORGANIZATION CLASSIFICATION OF TUMORS
Božo Krušlin, Tihana Džombeta, Davor Tomas, Monika Ulamec
Gleason score, a measure of tumor differentiation, is a standard part of prostatic adenocarcinoma pathology report. It represents the sum of the most common and the second most common histological patterns in tumor, and can have a score of 2 to 10. After the introduction of Gleason grading system, some disadvantages were noted in routine practice. The most commonly used patterns were 6 (3+3) and 7 (3+4 or 4+3). Over the years, the Gleason grading system underwent a few revisions. In the current 2016 WHO classification, a five-grade group system was accepted, which is easier to apply and has a much better correlation to prognosis and therapeutic needs of patients. The major differences between old and new grading systems are specified in this review.