Utility of Prostate Specific Antigen Density and Free to Total Prostate Specific Antigen Ratio for Detecting Prostate Cancer in Iranian Men: A Prospective Study of 187 Cases

Objectives: There have been several reports on different prostate cancer screening tests, which may improve the specificity in the early detection of prostate cancer. Cut-off values of these tests are mainly based on data from USA and Europe and may not be applicable to other races. We conducted this study to evaluate the utility of different screening tests for detecting prostate cancer in Iranian men. Patients and Methods: Between March 2007 and March 2008, 187 men with total prostate specific antigen (PSA) in the range of 2 to 20ng/ml and with no pretreatment of the prostate, underwent transrectal ultrasound guided prostatic biopsy for suspected prostate cancer. The diagnostic value of total PSA levels, the free to total PSA ratio (f/t PSA) and PSA density (PSAD) were compared using receiver operating characteristic curve analysis. Results: Prostate cancer was diagnosed in 101 (54.0%) of the 187 patients. There were significant differences between the groups in the age and all PSA related parameters. Areas under the curve of PSAD and f/t PSA were higher than that of total PSA indicating a better diagnostic accuracy. We also noted a significantly better performance for PSAD compared with f/t PSA in a subgroup of patients with total PSA between 2 and 10 ng/ml. Conclusion: PSAD was a better predictor of prostate cancer especially in men with PSA levels < 10 ng/ml.