目的探讨在PSA灰区(tPSA4-10ng/ml)前列腺特异性抗原(PSA)、游离前列腺特异性抗原/总前列腺特异性抗原(f/tPSA)、前列腺特异性抗原密度(PSAD)对前列腺增生症(BPH)、前列腺癌(PCa)的诊断效用。方法 162例患者经临床确诊后分为BPH组104例和PCa组58例,分别检测其血清PSA、f/tPSA、直肠超声检测前列腺体积并测算PSAD数值。结果 PCa组血清tPSA与BPH组之间差异无统计学意义(P>0.05)。PCa组血清f/tPSA较BPH组明显降低(P<0.01),PCa组PSAD值较BPH组明显升高(P<0.01)。随f/tPSA、PSAD升高,PCa诊断的敏感度也升高但特异度下降。PSAD对PCa诊断特异度明显高于f/tPSA比值。结论 f/tPSA比值和PSAD对诊断BPH、PCa具有重要意义。 Objective To investigate the effect of prostate specific antigen (PSA), free prostate specific antigen / total prostate specific antigen (f / tPSA) and prostate specific antigen density (PSAD) on the progression of benign prostatic hyperplasia (BPH), prostate cancer (PCa) diagnostic utility. Methods 162 patients were divided into BPH group (n = 104) and PCa group (n = 58). Serum PSA and f / tPSA were measured in 162 patients. Prostate volume was measured by rectal ultrasound and the value of PSAD was calculated. Results There was no significant difference between PCa group and BPH group (P> 0.05). The serum f / tPSA in PCa group was significantly lower than that in BPH group (P <0.01), and PSAD in PCa group was significantly higher than that in BPH group (P <0.01). With f / tPSA, PSAD increased, PCa diagnostic sensitivity but also increased specificity decreased. PSAD diagnosis of PCa specificity was significantly higher than the f / tPSA ratio. Conclusion The f / tPSA ratio and PSAD are of great importance in the diagnosis of BPH and PCa.