Results of central pathology review of prostatic biopsies in a contemporary series from a phase III, multicenter, randomized controlled trial (SHIP0804)

To investigate contemporary rates of variation in the biopsy Gleason grading in prostate cancer, between local and central pathologists, based on central review of the pathological slides from Seed and Hormone for Intermediate‐risk Prostate Cancer (SHIP) 0804, a phase III, multicenter, randomized, controlled study. From April 2008 to May 2011, 18 Japanese institutions participated. All H&E slides were reviewed independently, without clinical information, and a tumor grade was assigned according to the modified Gleason grading system proposed by the International Society of Urological Pathology (ISUP). Prostate biopsy specimens of 642 cases were available for evaluation. An exact concordance rate of Gleason score (GS) between local and central pathologists was determined to be 65.3%; with the under‐grading and over‐grading of grades to be 14.6% and 20.1%, respectively. The central review resulted in numbers of tumor‐bearing cores reassigned in 99 of 616 cases in which such information by the local pathologists was available (16.1%). Discordance in biopsy Gleason grading was still found in one third of the cases in the SHIP0804 study. This information is valuable in extrapolating the diagnostic error range in contemporary clinical studies conducted without central pathological review.