ABSTRACT
Objectives To explore the significance of measuring free/total(f/t) prostate-specification antigen (PSA) ratio, testosterone (T) and free testosterone (FT) in the patients with prostate cancer for performing biopsy with PSA values between 2 and 4 ng/ml.Methods The f/tPSA ratio and total and free testosterone levels in two hundred and seventy-five men with serum PSA values between 2 to 4 ng/ml were quantified.Serum free testosterone levels were measured by immuno-radiometric assay (IRMA), f/tPSA and testostorone levels were determined by chemiluminescence immunoassay (CLIA), underwent transrected ultrasound-guided biopsy (TRUS) was used as the diagnostic standard to detect the earlier prostate cancer in these patients. The diagnostic sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, and confidence interval of 95% were determined by receiver operating characteristic (ROC) curve.Results Prostate cancer was detected in 44 of 275 patients(16%). f/tPSA ratio and total and free testosterone levels in the patients with prostate cancer were significantly lower than those in nonprostatic cancer groups (P