ABSTRACT
PURPOSE: We investigated the value of the free to total PSA ratio of intermediate serum PSA levels(4-20ng/m1) in the detection of prostate cancer. MATERIALS AND METHODS: Free PSA, total PSA levels and free to total PSA ratio(F/T ratio) were measured on sera samples of 103 men with symptomatic BPH and 20 men with prostate cancer, who were proved by biopsy, by using ELSA-PSA2 and FPSA-RIACT. And we used transrectal ultrasound determined prostate volume to calculated PSA density(PSAD). RESULTS: In all patients, mean PSAD was significantly greater for patients with cancer(2.07+/- 1.65) versus BPH(0.120.12). The F/T ratio was significantly lower for cancer(0.12+/-0.04) compared with BPH(0.32+/-0.20). At a time, when serum PSA between 4 and 20ng/m1 was considered in 8 patients with cancer and 38 patients with BPH, mean total serum PSA was significantly greater for patients with cancer(12.02+/- 3.54ng/m1) versus BPH(7.21 +/-3.68ng/m1). Mean PSAD was significantly greater for patients with cancer(0.36+/- 0.12) versus BPH(0.20+/-0.12) and the F/T ratio was significantly lower for cancer(0.14+/-0.03) compared with BPH(0.25+/-0.12). Use of the Ff ratio of 0.15 resulted in the highest sensitivity(75%) and specificity(89.5%) and the F/T ratio was superior to total PSA when compared with receiver operating characteristic curve . CONCLUSIONS: The F/T ratio give a significant improvement over total PSA value in the diagnosis of prostate cancer in patients with intermediate PSA levels. But, to assess accurately usefullness of F/T ratio in early prostate cancer detection, further studies are needed and consensual threshold value is necessary.