role of free to total prostate specific antigen [PSA] and PSA density in improving the specificty of prostate cancer screening

The diagnostic value of serum prostate specific antigen [PSA] is limited by its lack of specificity. Measurement of the free to total PSA ratio [f/t PSA] and determination of PSA density [PSAD] has been used to improve the diagnostic accuracy of PSA. A total of 122 patients above the age of 50 years with a total serum PSA ranging between 4.1 - 10.0 ng/ml were screened for prostate cancer detection. All patients were subjected to total and free serum PSA concentrations with calculation of the f/t PSA ratio, digital rectal examination [DRE], transrectal ultrasound [TRUS], determination of PSAD and TURS- guided prostatic biopsy. Prostate cancer was diagnosed in 38 patients [31.15%] while benign prostatic hyperplasia [BPH] was confirmed in 84 patients [68.85%]. Mean f/t PSA ratio was significantly lower in patients with prostate cancer compared to those wih BPH [12.89 versus 23.18, p = 0.001]. At f/t PSA cutoff point of