Will the modification of the Gleason grading system affect the urology practice?

The aim of the present study was to determine how the modified Gleason grading (mGG) system affects the score discrepancy between needle biopsy (NB) and radical prostatectomy (RP) and to investigate the effect of the modified scores on nomogram predictions. When the conventional Gleason grading (cGG) and mGG systems were compared, a new Gleason score was obtained in the NBs for 40 out of 97 patients (41.2%; P < .001) and in the RP specimens for 15 out of 97 patients (15.5%; P = .005). The agreement between the NBs and RP specimens rose from 31.9% to 44.3% with the mGG system (P = .017). However, when the predictions calculated with the location of modified Gleason scores in the Memorial Sloan Kettering Cancer Center nomogram were compared with those of the conventional Gleason scores, higher pathological stage and lower life expectancy predictions were obtained. Therefore, when a clinician is making a choice from therapeutic options, this change should be taken into account.