Han Gang, Gao Jiang-ping, Cao Xi-liang, Hong Bao-fa, Tang Jie
Department of Urology, General Hospital of People's Liberation Army, Beijing 100853, China.
Zhonghua Wai Ke Za Zhi. 2006 Mar 15;44(6):379-81.
To investigate the usefulness of percentage of free prostate specific antigen (FPSA/TPSA) in serum/PSA density [(F/T)/PSAD] in the diagnosis of prostate cancer.
Two hundred and four patients who had been carried out transrectal ultrasound guided prostate biopsy, were involved in this study. Among them, 90 patients were proved to be suffering from prostate cancer, and other 114 patients were identified as benign prostate hypertrophy. The effect of total serum PSA level, FPSA/TPSA, PSAD and (F/T)/PSAD in the diagnosis of prostate cancer were investigated, and at the same time, selecting patients who should be carried out a prostate biopsy.
The mean values of (F/T)/PSAD were significantly lower for patients with prostate cancer in different PSA levels (<4.0, 4.0-, 10.1-, >20.0 microg/L), when compared with benign prostate hypertrophy patients. This difference has arrived statistical significance (P < 0.05). (F/T)/PSAD could provide higher specificity for diagnosing prostate cancer than FPSA/TPSA or PSAD. Among all patients, at the same higher sensitivity (about 90%), the specificity of FPSA/TPSA, PSAD and (F/T)/PSAD was 31.6%, 45.6% and 64.0%, respectively. At the same time, it was suggested that clinicians use different cutoffs for (F/T)/PSAD in different PSA level. When PSA level of patients was no more than 4.0 microg/L, 2.5 as the commended cutoff for (F/T)/PSAD was preferred; if PSA level was between 4.0 microg/L and 20.0 microg/L, 0.8 was a more suitable cutoff; 0.5 also could be taken as an appropriate cutoff in case of PSA level being higher than 20.0 microg/L.
Keeping high sensitivity, using of (F/T)/PSAD can improve the diagnostic specificity of prostate cancer significantly.
探讨血清游离前列腺特异性抗原百分比（FPSA/TPSA）与前列腺特异性抗原密度[（F/T）/PSAD]在前列腺癌诊断中的应用价值。
204例行经直肠超声引导下前列腺穿刺活检的患者纳入本研究。其中，90例被证实患有前列腺癌，另外114例被诊断为良性前列腺增生。研究总血清PSA水平、FPSA/TPSA、PSAD及（F/T）/PSAD在前列腺癌诊断中的作用，同时筛选出需要进行前列腺穿刺活检的患者。
不同PSA水平（<4.0、4.0 -、10.1 -、>20.0μg/L）的前列腺癌患者，其（F/T）/PSAD均值显著低于良性前列腺增生患者。差异具有统计学意义（P<0.05）。与FPSA/TPSA或PSAD相比，（F/T）/PSAD对前列腺癌的诊断具有更高的特异性。在所有患者中，当敏感性均较高（约90%）时，FPSA/TPSA、PSAD及（F/T）/PSAD的特异性分别为31.6%、45.6%和64.0%。同时建议临床医生在不同PSA水平下采用不同的（F/T）/PSAD临界值。当患者PSA水平不超过4.0μg/L时，推荐（F/T）/PSAD的临界值为2.5；若PSA水平在4.0μg/L至20.0μg/L之间，0.8是更合适的临界值；当PSA水平高于20.0μg/L时，0.5也可作为合适的临界值。
（F/T）/PSAD在保持高敏感性的同时，可显著提高前列腺癌的诊断特异性。
