游离前列腺特异抗原百分比/前列腺特异抗原密度在前列腺癌诊断中的应用

目的探讨游离前列腺特异抗原百分比（FPSA／TPSA值）／前列腺特异抗原密度（F／T）／PSAD值]在前列腺癌诊断中的意义。方法回顾分析204例行经直肠超声引导前列腺穿刺活检患者的诊断资料,其中前列腺癌90例、良性前列腺增生114例,分析总PSA（TPSA）、FPSA／TPSA值、PSAD、（F／T）／PSAD值等指标在判断前列腺癌的敏感性为90％时的截点及相应的特异性。结果不同血清PSA水平（〈4．0,4．0～,10．1～和〉20．0μg／L）的前列腺癌患者的（F／T）／PSAD值与良性前列腺增生患者比较,差异有统计学意义（P〈0．05）;前列腺癌患者的（F／T）／PSAD值低于良性前列腺增生患者;（F／T）／PSAD值比FPSA／TPSA值和PSAD更有助于提高诊断特异性,在敏感性为90％左右的前提下,FPSA／TPSA值的特异性为31．6％,PSAD的特异性为45．6％,（F／T）／PSAD值的特异性为64．0％;PSA水平不同,取的（F／T）／PSAD值截点也不同：PSA〈4．0μg/L时截点为2．5,PSA为4．0～20．0μg／L时截点为0．8;PSA〉20．0μg／L时截点为0．5。结论应用（F／T）／PSAD值能够在保持较高敏感性的前提下,显著提高前列腺癌诊断的特异性。

The usefulness of percentage of free prostate specific antigen/prostate specific antigen density in the diagnosis of prostate cancer

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Keeping high sensitivity, using of (F/T)/PSAD can improve the diagnostic specificity of prostate cancer significantly.