780 Ki67 may be a Useful Biomarker in the Assessment of Risk in Testicular Sex-Cord Stromal Tumours

Abstract

Disclosures: Pascale Capleton: None; Helgaud Gerard: None; Kenrick Ng: None; Jonathan Shamash: None; Luis Beltran Fernandez: None; Daniel Berney: None Background: Testicular sex-cord stromal tumours (SCST) may be unpredictable in behaviour and the risk of malignancy may be challenging to determine. The Testicular Sex-Cord Stromal Group of expert pathologists (supported by GUPS and ISUP) met at USCAP 2024 and agreed that there was insufficient evidence for Ki67 to be a routine biomarker in determining metastatic risk in SCSTs and that further work was needed. It has been the practice at our institution to perform Ki67 in SCSTs and therefore we wished to perform a retrospective audit of our data to compare Ki67 with the established criteria for predicting SCST behaviour and outcomes.