Low-Risk Prostate Cancer and Tumor Upgrading to Higher Patterns in the Surgical Specimen. Analysis of Clinical Factors Predicting Tumor Upgrading to Higher Gleason Patterns in a Contemporary Series of Patients Who Have Been Evaluated According to the Modified Gleason Score Grading System

Objective: To identify clinical factors associated with prostate cancer (PCA) upgrading to higher patterns of the surgical specimen in low-risk PCA. Materials and Methods: We evaluated the records of 438 patients. The multinomial logistic regression model was used. Results: Low-risk PCA included 170 cases (38.8%) and tumor upgrading was detected in 111 patients (65.3%) of whom 72 (42.4%) had pathological Gleason patterns (pGP) = 3 + 4 and 39 (22.9%) pGP >3 + 4. Prostate-specific antigen (PSA) and proportion of positive cores (P+) were independent predictors of tumor upgrading to higher patterns. The main difference between upgraded cancers related to PSA and to P+ >0.20. The population was stratified into risk classes by PSA ≤5 μg/l and P+ ≤0.20 (class A), PSA >5 μg/l and P+ ≤0.20 (class B), PSA ≤5 μg/l and P+ >0.20 (class C) and PSA >5 μg/l and P+ 0.20 (class D). Upgrading rates to pGP >3 + 4 were extremely low in class A (5.1%), extremely high in D (53.8%). Conclusions: Low-risk PCA is a heterogeneous population with significant rates of undetected high-grade disease. Significant clinical predictors of upgrading to higher patterns include PSA and P+, which identify a very high-risk class that needs repeat biopsies in order to reclassify tumor grade.