Incidence of Pathological Downgrading and Treatment Outcome After Radical Prostatectomy in Patients With Biopsy Confirmed High Gleason Score Prostate Cancer

ABSTRACT

PURPOSE: High Gleason score (8 to 10) is a poor prognostic factor regardless of treatment. Pathological downgrading sometimes occurs in high grade prostate cancer. The aim of this study is to evaluate treatment outcomes in patients with high grade prostate cancer on biopsy who were pathological downgrading after radical prostatectomy (RP). The impact on outcomes according to changes in the Gleason score after RP was evaluated. MATERIALS AND METHODS: Of 3,236 men who underwent RP between September 1995 and December 2014, 541 patients with biopsy Gleason score 8 to 10 were retrospectively reviewed. We analyzed incidence and biochemical recurrence (BCR) free probability in this downgraded group according to the Gleason grade of cancer in the RP specimen. RESULTS: Of 541 patients had a prostate biopsy Gleason score of 8 to 10. Two hundred ten patients showed pathological downgrading after RP (38.8%). Five-year BCR-free probability of patients who had Gleason score of 7 or less after RP was 46.8%. However, 5-year BCR-free probability of patients who remained Gleason scores 8 to 10 after RP was 28.5%. There was a significantly higher BCR-free probability in pathological downgrading group (p<0.001). On multivariate analysis, biopsy Gleason 8, lower PSA, clinical T2 stage was a significant predictor of downgrading. CONCLUSIONS: In this study, 38.8% of patients with high grade prostate cancer had a Gleason score of 7 or less in the RP specimen. Downgraded prostate cancer had more favorable treatment outcome. Serum PSA, clinical stage and biopsy Gleason score were the predictive factors for pathological downgrading.