THE IMPACT OF PROSTATE-SPECIFIC ANTIGEN DENSITY IN PREDICTING PROSTATE-CANCER WHEN SERUM PROSTATE-SPECIFIC ANTIGEN LEVELS ARE LESS-THAN 10 NG ML/

Objective: To evaluate the impact of prostate-specific antigen density (PSAD) when serum levels of prostate-specific antigen (PSA) are less than 10 ng/ml. Methods: We retrospectively analyzed 134 patients who u nderwent transrectal ultrasound (TRUS)-guided prostate biopsies accord ing to Cooner's algorithm. Results: Histopathological examination reve laed prostate cancer (PCa) in 22 (16%) and benign prostatic hypertroph y (BPH) in 112 (84%) patients. Five patients (23%) with PCa had PSAD < 0.15 of whom 3 had PSA < 4 ng/ml and 2 had PSA between 4 and 10 ng/ml . In the BPH group, 60 patients (54%) had PSAD below 0.15 whereas 52 p atients (46%) had PSAD over 0.15. With 0.15 as the cutoff level of PSA D, the sensitivity and specificity of PSAD was found as 77 and 54%, re spectively. In this patient population, PSA with the cutoff level of 4 ng/ml has sensitivity and specificity levels of 77 and 33%, respectiv ely. According to these results, a statistically significant differenc e was found between PSA and PSAD only in terms of diagnostic specifici ty (chi-square, p < 0.05). There were 29 patients with negative digita l rectal examination (DRE) and TRUS and PSA 4-10 ng/ml who underwent b iopsy because of PSAD > 0.15. No cancer was detected in this group of patients, suggesting that biopsy in this subgroup may be unnecessary. Conclusion: Although PSAD seemed to increase the specificity without a ny decrease in sensitivity in the diagnosis of prostate cancer, it did not bring any practical advantage in our selected population since al l PCa cases had abnormal DRE and/or TRUS findings.