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 underwent transrectal ultrasound (TRUS)-guided prostate biopsies according to Cooner's algorithm. Results: Histopathological examination revelaed prostate cancer (PCa) in 22 (16%) and benign prostatic hypertrophy (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 patients (46%) had PSAD over 0.15. With 0.15 as the cutoff level of PSAD, the sensitivity and specificity of PSAD was found as 77 and 54%, respectively. In this patient population, PSA with the cutoff level of 4 ng/ml has sensitivity and specificity levels of 77 and 33%, respectively. According to these results, a statistically significant difference was found between PSA and PSAD only in terms of diagnostic specificity (chi-square, p < 0.05). There were 29 patients with negative digital rectal examination (DRE) and TRUS and PSA 4-10 ng/ml who underwent biopsy 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 any decrease in sensitivity in the diagnosis of prostate cancer, it did not bring any practical advantage in our selected population since all PCa cases had abnormal DRE and/or TRUS findings.