Within the Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative, 25 centers across the globe collaborate to standardize active surveillance (AS) protocols for men with low-risk prostate cancer (PCa). A centralized PCa AS database, comprising data of more than 15 000 patients worldwide, was created. Comparability of the histopathology between the different cohorts was assessed by a centralized pathology review of 445 biopsies from 15 GAP3 centers. Grade group 1 (Gleason score 6) in 85% and grade group ≥2 (Gleason score ≥7) in 15% showed 89% concordance at review with moderate agreement (κ = 0.56). Average biopsy core length was similar among the analyzed cohorts. Recently established highly adverse pathologies, including cribriform and/or intraductal carcinoma, were observed in 3.6% of the reviewed biopsies. In conclusion, the centralized pathology review of 445 biopsies revealed comparable histopathology among the 15 GAP3 centers with a low frequency of high-risk features. This enables further data analyses—without correction—toward uniform global AS guidelines for men with low-risk PCa. Patient summary: Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative combines data from 15 000 men with low-risk prostate cancer (PCa) across the globe to standardize active surveillance protocols. Histopathology review confirmed that the histopathology was consistent with low-risk PCa in most men and comparable between different centers. A centralized pathological review showed consistent biopsy quality and Gleason grading within the global active surveillance Global Action Plan 3 initiative, a prerequisite for future studies toward uniform global guidelines for active surveillance of men with low-risk prostate cancer.

Additional Metadata
Keywords Active surveillance, Biopsy quality, GAP3 consortium, Gleason grading, Pathology review, Prostate cancer
Persistent URL dx.doi.org/10.1016/j.euo.2018.08.017, hdl.handle.net/1765/117391
Journal European Urology Oncology
van der Kwast, Th.H, Helleman, J. (Jozien), Nieboer, D, Bruinsma, S.M, & Roobol-Bouts, M.J. (2019). Consistent Biopsy Quality and Gleason Grading Within the Global Active Surveillance Global Action Plan 3 Initiative: A Prerequisite for Future Studies. European Urology Oncology, 2(3), 333–336. doi:10.1016/j.euo.2018.08.017