Objective: To investigate the influence of the revised Gleason grading system (GGS, revised at a consensus conference organized by the International Society of Urological Pathology in 2005) on prediction of prognosis for patients with prostate cancer with bone metastasis.
Patients and methods: Prostatic needle biopsy specimens from 113 patients with prostate cancer with bone metastasis were scored using the conventional GGS (CGGS), modified global GGS (MGGGS), and modified highest GGS (MHGGS). The patients were divided into two groups (Gleason score < or = 7 and > or = 8) using each grading system. Prostate-specific antigen failure-free survival after hormone therapy (HT) was estimated retrospectively. The Cox proportional hazard method was used for univariate and multivariate analysis.
Results: Patients with a Gleason score of < or = 7 had a significantly longer remission than patients with a score of > or = 8 according to each GGS. However, the better prognosis patients were detected more precisely by the CGGS and MGGGS than the MHGGS. Multivariate analysis showed that the CGGS and MGGGS were significant prognostic indicators for the outcome of HT after adjustment for other prognostic factors.
Conclusions: These results suggest that the CGGS and MGGGS are more useful than the MHGGS as prognostic indicators for HT. Further evaluation in larger series is needed to define its clinical usefulness.