The aim of this study was to explore the predictors of International Society of Urological Pathology (ISUP) Grade Group (GG) upgrading in nonclinically significant prostate cancer (non-csPCa) biopsy specimens guided by transrectal ultrasound (TRUS) following radical prostatectomy (RP). A retrospective analysis was conducted on clinical data from 231 patients who underwent TRUS-guided biopsy and RP between January 2018 and December 2023. Univariate and multivariate logistic regression analyses were employed to identify independent predictors of postoperative ISUP GG upgrading. The diagnostic efficiency of these predictors was evaluated using receiver operating characteristic (ROC) curves. Additionally, ROC analysis was used to compare the predictive performance of different positive target (PT) imaging methods across prostate volume (PV) subgroups. The study included 111 (48.1%) patients in the GG concordance group and 120 (51.9%) patients in the GG upgrading group. Univariate analysis revealed that PV, prostate-specific antigen density, Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1), magnetic resonance imaging (MRI) PT, contrast-enhanced ultrasound (CEUS) PT, and clinical T stage significantly influenced GG upgrading (all P < 0.05). Multivariate logistic regression revealed PV (OR = 0.974; 95% CI: 0.955–0.994; P = 0.010), MRI PT (OR = 3.902; 95% CI: 1.507–10.102; P = 0.005), and CEUS PT (OR = 2.280; 95% CI: 1.073–4.845; P = 0.032) as independent predictors. The prediction model demonstrated the highest diagnostic performance (area under the receiver operating characteristic curve [AUC] = 0.738, P < 0.001). MRI PT showed superior predictive efficacy compared with CEUS PT in patients with a PV <30.13 ml. In conclusion, PV, CEUS PT, and MRI PT were identified as independent predictors of postoperative ISUP GG upgrading. The predictive model exhibited the best overall performance, and compared with CEUS PT, MRI PT demonstrated greater predictive accuracy for smaller prostates.

Keywords: biopsy; International Society of Urological Pathology Grade Group; prostate cancer; radical prostatectomy; upgrading