Background: To investigate the role of Cumulative Cancer Length (CCL) and PCa positive core number (PCapcn) in random prostate biopsies as predictors of Adverse Pathology (AP) at definitive pathology. Methods: We prospectively enrolled patients submitted to random ultrasound guided prostate biopsies for suspect PCa in our center since 2016. Inclusion criteria were PSA 3 ng/ml and age2mm) or PCa Positive Lymph Node. ROC curve was used to establish an appropriate CCL and PCapcn thresholds that were then investigated as predictors of AP at definitive pathology. Results: Among 882 eligible biopsies, 344 had PCa and underwent RP. Mean age was 64 years (SD 5). Mean PSA was 7.75 (SD: 3.66). At definitive pathology there were AP features in 196 (56.9%) RP. PCapcn and CCL were statistically significantly associated with AP (p6mm and PCapcn >3 thresholds for AP were established (Area: 0.769; p6mm AP had OR 5.462 (CI 95% 2.717-10.978) p3 had OR 7.127 (CI 95% 3.366-15.090) p6mm had OR 3.989 (CI 95% 1.839-8.652) p3 had OR 5.541 (CI 95% 2.390-12.849) p6mm or PCapcn >3 might be associated with AP features, in particular for low and favorable intermediate risk PCa. Keywords: Prostate cancer, Prostate biopsy, Upgrading, Adverse pathology, Clinically significant prostate cancer