Improved accuracy in predicting the presence of Gleason pattern 4/5 prostate cancer by three-dimensional 26-core systematic biopsy

OBJECTIVES: To evaluate whether three-dimensional 26-core (3D26) prostate biopsy improves the accuracy in predicting the presence of Gleason pattern 4/5 cancer compared with extended transrectal 12-core (TR12) or transperineal 14-core (TP14) biopsy schemes. METHODS: We studied 143 consecutive men in whom prostate cancer was diagnosed by the 3D26 biopsy and who underwent radical prostatectomy (RP) without neoadjuvant treatment. All histologic grading was reevaluated by a single pathologist according to the 2005 International Society of Urological Pathology Consensus Conference on Gleason Grading. Cancer grade was categorized into high grade (Gleason pattern 4/5 cancer present) and non-high grade (absent) in both biopsy and RP specimens. Since TR12 and TP14 biopsy schemes represent subsets of the 3D26 biopsy, we could compare these schemes directly in an identical patient cohort. RESULTS: There was a grade agreement between 3D26 biopsy and RP in 132 (92.3%) cancers. Grade concordance between biopsy and RP was significantly better in 3D26 biopsy than in TR12 (83.5%, p=0.025) biopsy. Risk of underestimation of cancer grade by 3D26 biopsy (26.5%) was significantly lower than that by TP14 (51.4%, p=0.034). Grade concordance between 3D26 biopsy and RP was not according to clinical variables including prostate volume, clinical stage, prostate-specific antigen (PSA), and PSA density. CONCLUSIONS: We demonstrated that the 3D26 biopsy can accurately predict the presence of Gleason pattern 4/5 cancer on RP specimens with a high concordance rate of 92.3%, a value significantly higher than that between extended TR12 biopsy and RP specimens.