biostudies-literatureUnknown487(1)Hommerding OUniversitätsklinikum BonnThe prognostication of individual disease trajectory and selection of optimal therapy in patients with localized, low-grade prostate cancer often presents significant difficulty. The phosphatase and tensin homolog on chromosome 10 (PTEN) has emerged as a potential novel biomarker in this clinical context, based on its demonstrated prognostic significance in multiple retrospective studies. Incorporation into standard clinical practice necessitates exceptional diagnostic accuracy, and PTEN's binary readout-retention or loss-suggests its suitability as a biomarker. This multi-institutional ring trial aimed to validate the diagnostic precision of PTEN immunohistochemistry in localized, low- to intermediate-risk prostate cancer, across ten university pathology institutes in Germany. The trial iVirchows Archiv : an international journal of pathology87-96https://www.ebi.ac.uk/biostudies/studies/S-EPMC12289804biostudies-literatureHigh interobserver variability of PTEN immunohistochemistry defining PTEN status in low- to intermediate-risk prostate cancer: results of the first German ring trial.PMC12289804Semjonow AReis HKristiansen GSchmid MLinxweiler JSchildhaus HUBrasen JHDarr CWulf ALBaretton GSeidl MEsposito IStahl PRKreipe HSchlack KHartmann WAbbas MHommerding OLopez-Cotarelo CScherping ADressler FFHartmann ASaar MWeber FEllinger JLafos MSailer VTischler VBernhardt MKreft TSommer UBreyer JHeitplatz BErber RWullich BfalseHigh interobserver variability of PTEN immunohistochemistry defining PTEN status in low- to intermediate-risk prostate cancer: results of the first German ring trial.The prognostication of individual disease trajectory and selection of optimal therapy in patients with localized, low-grade prostate cancer often presents significant difficulty. The phosphatase and tensin homolog on chromosome 10 (PTEN) has emerged as a potential novel biomarker in this clinical context, based on its demonstrated prognostic significance in multiple retrospective studies. Incorporation into standard clinical practice necessitates exceptional diagnostic accuracy, and PTEN's binary readout-retention or loss-suggests its suitability as a biomarker. This multi-institutional ring trial aimed to validate the diagnostic precision of PTEN immunohistochemistry in localized, low- to intermediate-risk prostate cancer, across ten university pathology institutes in Germany. The trial i2025-01-01T00:00:00Z2025 Jul2026-03-17T13:41:58.906Z2025-08-28T03:04:47.073ZS-EPMC122898043965382810.1007/s00428-024-03999-y