Grade Groups Provide Improved Predictions of Pathological and Early Oncologic Outcomes Compared with Gleason Score Risk Groups

Purpose:The GG (Grade Group) system was introduced in 2013. Data from academic centers suggest that GG better distinguishes between prostate cancer risk groups than the Gleason score (GS) risk groups. We compared the performance of the 2 systems to predict pathological/recurrence outcomes using data from the MUSIC (Michigan Urological Surgery Improvement Collaborative).Materials and Methods:Patients who underwent biopsy and radical prostatectomy in the MUSIC from March 2012 to June 2017 were classified according to GG and GS. Outcomes included the presence or absence of extraprostatic extension, seminal vesical invasion, positive lymph nodes, positive surgical margins and time to cancer recurrence (defined as postoperative prostate specific antigen 0.2 ng/ml or greater). Logistic and Cox regression models were used to compare the difference in outcomes.Results:A total of 8,052 patients were identified. When controlling for patient characteristics, significantly higher risks of extraprostatic extension, se...