Zengin, MehmetEryol, MerveAkkaya, Merva AydemirBalcı, MahiYalçın, SelimTuğlu, Devrim2025-01-212025-01-2120202636-8579https://doi.org/10.32322/jhsm.758558https://search.trdizin.gov.tr/tr/yayin/detay/500028https://hdl.handle.net/20.500.12587/22932Aim: Prostate cancer is the most common malignant tumour in men. The most widely used histological grading scheme for prostate cancer is Gleason scoring. After the original, this system has been modified several times. In this study, we retrospectively investigated the new Grade-group system (GGS). Material and Method: This study includes 486 cases diagnosed with prostate cancer between 2000 and 2015. All cases were re-grouped for the new Grade-group system and its relationship with prognosis was examined. Results: Grade-group system subgroups had a statistically significant relationship between prognostic factors and this relationship was more significant between GGS 2 and GGS 3 [tumor status (p<0.001), age (p=0.045), PN invasion (p<0.001), stage (p=0.004), and LN status (p<0.001)]. In univariable survival analysis, there was a significant difference between Grade-group system subgroups (for GGS 2-GGS 3, RFS: p=0.035 and OS: p=0.012; for GGS 4-GGS 5, RFS: p=0.001 and OS: p=0.001). In multivariable survival analysis, GGS subgroups were found to be an independent survival parameter for prostate cancer (for GGS 2-GGS 3, OS: HR=2.56, p=0.012 and RFS: HR=2.69, p=0.038; for GGS 4-GGS 5, OS: HR=2.84, p=0.011 and RFS: HR=2.59, p<0.001). Conclusions: According to our results, the new Grade-group system performs the prognostic risk grading more accurately than the old classification. Also, the fact that this system contains fewer categories and is simpler has increased the interobserver compatibility.eninfo:eu-repo/semantics/openAccessPatolojiOnkolojiArticle3438238810.32322/jhsm.758558500028