通过比较血清总前列腺特异性抗原（tPSA）、游离前列腺特异性抗原（fPSA）与年龄预测前列腺体积（PV）大小的准确性，寻找预测PV简便易行、较准确的预测因子。

收集2005年1月至2014年12月因下尿路症状到我院诊治下尿路症状/良性前列腺梗阻（LUTS/BPO）患者的年龄、PV及PSA检测值；采用SPSS 13.0软件处理数据，用皮尔森线性相关关系描述年龄、血清tPSA及血清fPSA与PV的相关性，并采用卡方检验及受试者特征曲线（ROC）分析比较血清tPSA、血清fPSA预测PV的准确性。

入选6 308例男性，皮尔森线性相关分析显示年龄-PV、tPSA-PV和fPSA-PV的相关系数分别是0.197、0.434、和0.446，其P值均<0.05，具有相关性；在tPSA为0~4 μg/L时，tPSA和fPSA预测PV在（30~50）ml、（50~70）ml和PV>70 ml组的AUC-ROC分别为（0.617、0.732、0.761）和（0.625、0.738、0.767）；在tPSA为0~4 μg/L时，tPSA和fPSA预测PV在（30~50）ml、（50~70）ml和PV>70 ml组的最佳临界值分别为tPSA（1.3 μg/L、1.6 μg/L、2.0 μg/L）和fPSA（0.3 μg/L、0.4 μg/L、0.5 μg/L）。

中国LUTS/BPO男性血清fPSA与PV正相关程度最高，血清tPSA与fPSA均可作为独立预测因子预测中国LUTS/BPO男性的PV，可作为临床上预测PV简便易行的指标，其中fPSA预测的准确性更高。

To compare the accuracy of serum total prostate-specific antigen (tPSA), free PSA (fPSA) and age in predicting prostate volume (PV), aiming to identify the simple and accurate biomarkers for predicting PV.

Age, PV, and PSA values of patients diagnosed with lower urinary tract symptoms/benign prostatic obstruction (LUTS/BPO) admitted to our hospital from January 2005 to December 2014 were collected. The data was processed using SPSS 13.0 statistical software. Pearson's linear correlation was utilized to describe the correlation between age, serum tPSA, serum fPSA and PV. Chi-square test and the receiver characteristic curve (ROC) were used to analyze and compare the accuracy of serum tPSA and fPSA in predicting PV.

A total of 6308 male patients were enrolled. Pearson's linear correlation analysis demonstrated that the correlation coefficients of age-PV, tPSA-PV and fPSA-PV were 0.197, 0.434, and 0.446, respectively (all P<0.05). When tPSA was 0-4 μg/L, the AUC-ROC of tPSA and fPSA in predicting PV in the (30-50), (50-70) and >70 ml groups were (0.617, 0.732, 0.761) and (0.625, 0.738, 0.767), respectively. When tPSA was 0-4 μg/L, the optimal cut-off values of tPSA and fPSA in predicting PV in the (30-50), (50-70), and PV> 70 ml groups were (1.3 μg/L, 1.6 μg/L, 2.0 μg/L)and (0.3 μg/L, 0.4 μg/L, 0.5 μg/L), respectively.

The serum fPSA possesses the highest positive correlation with PV in the male LUTS/BPO patients in China. Serum tPSA and fPSA can be considered as independent biomarkers to predict the PV in this population, which can be used as simple and convenient predictors for PV in clinical practice. fPSA yields higher prediction accuracy compared with tPSA.