Prostate specific antigen density with a cut-off point of 0.12 is the best predictor of cancer on prostate biopsies

Abstract

Introduction: Prostate cancer (PCa) is the second most frequent type of cancer in men; diagnosis is reached through prostate biopsy, an invasive procedure, so efforts are made to avoid unnecessary ones by improving them and optimizing current biomarkers. Among existing biomarkers, prostate -specific antigen (PSA) Density (PSAD), a PSA derivative, is considered a feasible biomarker for PCa Objective: This study aimed to evaluate different PSA derivatives as well as determine whether PSAD with a cut-off point of 0.12 was more accurate than the widely used value of 0.15 to recognize patients suffering from prostate cancer. Material and methods: Retrospective study of 391 patients aged 40 years or more, who underwent prostate biopsy at Fundacion Urologica Cordoba para la Docencia e Investigacion Medica (FUCDIM) , from November 2010 to July 2014. Sensitivity and specificity for the PSAD cut-off point of 0.12 were estimated. Diagnostic accuracy was evaluated through Receiver Operating Characteristic (ROC) curves and the Area Under the Curve. PSAD was compared to total PSA, free/total PSA index, and (free/total PSA)/PSAD. Results: Significantly higher mean values were found in terms of total PSA, PSAD, and F/T PSA in patients with confirmed diagnoses of PCa. PSAD with a cut-off point greater than 0.12 detected a significantly higher percentage of cancer, 80%, p=0.0001, compared to the control group. Furthermore, the strength of association determined that patients with PSAD greater than 0.12 were 3 times more likely to belong to the PCa group. Conclusion: Total PSA, PSAD, and F/T PSA in patients with cancer yielded significantly higher mean values. The best biomarker to predict prostate cancer by biopsy was PSAD, with a cut-off point of 0.12. These results indicate the need to develop further investigations in diverse geographic areas to define the best local cut-off points for PSAD. Our results demonstrate that the established cut-off point of 0.15 could be appropriate for European men but appears to be too high for American and low for Asian males.