Immunoradiometric assay of total PSA, Free PSA and PSA ratio calculation in prostatic cancer (PCa) diagnosis

Total PSA assay is a well established procedure for biochemical evaluation and management of PCa which usefulness in its diagnosis is limited by its weak specificity with regard to BPH. Recently the assay of Free- PSA and the calculation of Free/Total-PSA Ratio has been suggested to improve the specificity of PSA in the range of concentrations between 2.5 and 20 ng/mL. We evaluated the diagnostic performance of PSA-Ratio among untreated patients with PSA levels ranging from 2.5 to 20 ng/mL and histological diagnosis of PCa or BPH. As the ROC curves analysis stowed PSA-Ratio is the better parameter to discriminate between PCa and BPH: PSA-Ratio could be employed to enhance the diagnostic performance of PSA alone in PCa diagnosis.