Prostate-specific antigen levels and proportion of biopsy positive cores are independent predictors of upgrading patterns in low-risk prostate cancer.

Background: The aim of this study is to evaluate clinical factors associated with the risk of tumor upgrading patterns in low risk prostate cancer (PCA) patients undergoing radical prostatectomy.
Methods: In a period running from January 2013 to December 2016, 245 low risk patients underwent RP. Patients were classified into three groups, which included case with pathology grade group one (no upgrading pattern), two-three (intermediate upgrading pattern), and four-five (high upgrading pattern). The association of factors with the upgrading risk was evaluated by the multinomial logistic regression model. It was used a receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis to assess the efficacy of predictors.
Results: Overall, tumor upgrading was detected in 158 patients (67.3%). Tumor upgrading patterns were absent in 80 patients (32.7%), intermediate in 152 cases (62%) and high in 13 subjects (5.3%). Median prostate specific (PSA) levels and proportion of biopsy positive core (BPC) were higher in patients with intermediate (PSA=6 ng/mL; BPC=0.28) and high (PSA=8.9 ng/mL; BPC=0.33) than those without (PSA=5.7 ng/mL; BPC=0.17) and the difference was significant (PSA: P=0.002; BPC: P=0.001). When compared to not upgraded cases, higher BPC proportions were independent predictors of intermediate upgrading patterns (odds ratio, OR=36.711; P<0.0001; AUC=0.613) while higher PSA values were independent predictors of high upgrading patterns (OR=2.033, P<0.0001; AUC=0.779).
Conclusions: PSA and BPC were both independent predictors of tumor upgrading in low risk PCA. BPC associated with the risk of intermediate tumor upgrading patterns, but showed a low discrimination power. PSA associated with high upgrading patterns and showed a fair discrimination power in the model. Tumor upgrading risk patterns should be evaluated in low risk PCA patients before treatment.