Concordance of Gleason score on biopsy and after prostatectomy: A SEER database analysis.

Abstract

50 Background: The Gleason score (GS) is a well-established prognostic factor and is used to guide clinical decision-making for patients with prostate cancer. Concordance between the clinical GS of the core biopsy and of the pathologic specimen after radical prostatectomy has ranged from 30% to 75% in prior single-institution studies. The objective of this study is to analyze biopsy concordance utilizing the population-based Surveillance, Epidemiology, and End Results (SEER) database. Methods: Patients diagnosed with localized prostate adenocarcinoma (cT1c-4 Nx-1 M0) who underwent prostatectomy from 2010-2011 were identified in the SEER database. Agreement between clinical and pathologic GS was analyzed using the kappa (k) statistic. Univariate and multivariate logistic regression was performed to identify factors which may impact concordance using SPSS v21. Results: A total of 34,195 patients were included in this analysis. Median age was 61 and median PSA was 5.9 ng/ml. The majority of patients had clinical GS of 6 or 7 (76.5 %) and PSA < 10 ng/ml (77.4%). Overall concordance was 55.4% with k of 0.36, indicating fair agreement. Results are summarized in the Table. Of patients with clinical GS 6, concordance was 55.3%, with 43.1% upgraded to pathologic GS 7. Among patients with clinical GS 7, concordance was 66.9% for GS 3+4 and 42.9% for GS 4+3. Concordance was 24.8% among patients with clinical GS 8, with 57.4% downgrade rate. On multivariate analysis, Black race, increasing age, higher PSA and SEER registries California, Connecticut, Hawaii and Iowa predicted for decreased likelihood of concordance. Conclusions: This is, to our knowledge, the largest contemporary study of prostate biopsy concordance. We found a substantial rate of upgrade from GS 6 or 7 as well as significant downgrade from GS 8. Further investigation is needed to determine other potential factors to predict biopsy concordance. [Table: see text]