复合前列腺特异性抗原在诊断前列腺癌转移中的价值

The usefulness of complexed prostate-specific antigen in predicting metastasis in patients with prostate cancer

目的 探讨复合前列腺特异性抗原（complexed prostate-specific antigen,cPSA）相关指标在诊断前列腺癌转移中的应用价值. 方法 回顾性分析2012年1月至2014年4月收治的74例采用经直肠超声引导穿刺活检或术后病理初诊为前列腺癌患者的临床资料.根据有无转移分为转移组38例,其中骨转移36例,仅肺转移和仅淋巴结转移各1例,T1-T2期10例,T3- T4期28例;未转移组36例,T1-T2期17例,T3-T4期19例;两组中位年龄均为70岁;两组的T分期和年龄比较差异均无统计学意义（P＞0.05）.采用化学发光法检测两组的血清cPSA,电化学发光法检测tPSA、fPSA水平,分别计算两组的fPSA/tPSA、cPSA/tPSA.分析年龄同tPSA、cPSA的相关性,比较两组间PSA水平、fPSA/tPSA、cPSA/tPSA的差异.应用ROC曲线分析cPSA、tPSA对前列腺癌转移的诊断价值,采用Z检验比较cPSA、tPSA的ROC曲线下面积. 结果 本研究74例患者的年龄与tPSA（r=-0.09,P=0.12）和cPSA（r=-0.38,P=0.14）均无明显相关性.未转移组中位tPSA为29.88 μg/L,fPSA为2.18 μg/L,cPSA为18.86 μg/L;转移组tPSA为410.05 μg/L,fPSA为51.50 μg/L,cPSA为290.40 μg/L,两组间比较差异均有统计学意义（P＜0.05）.未转移组fPSA/tPSA为0.07,cPSA/tPSA为0.79;转移组fPSA/tPSA为0.08,cPSA/tPSA为0.80,两组间比较差异均无统计学意义（P＞0.05）.tPSA的ROC曲线下面积为0.83（95％ CI：0.73 - 0.93）,cPSA为0.82（95％ CI：0.73 - 0.92）,两者比较差异无统计学意义（Z=1.64,P=0.10）.以非转移组为对照,在敏感性为92.1％时,cPSA诊断前列腺癌转移的特异性（22.2％）高于tPSA（19.4％）.当tPSA的临界值为9μg/L或cPSA的临界值为7μg/L时,诊断前列腺癌转移的敏感性可达90.0％. 结论 cPSA在辅助诊断前列腺癌转移方面有一定的使用价值.

Objective To determine the value of complexed prostate-specific antigen （cPSA） in predicting metastasis in patients with prostate cancer.Methods From January 2012 to April 2014,the clinical data of 74 patients with newly diagnosed prostate cancer in our hospital was retrospective reviewed.The prostate cancer was diagnosed by transrectal ultrasound guided biopsy and postoperative pathologic diagnosis.The patients were divided to 2 groups according to metastases status.There were 38 patients in the group of metastasis and 36 patients in the group of without metastasis.In metastasis group,the bone metastasis was found in 36 cases.There is only one case with lung metastasis and one case with lymph node metastasis.In the group without metastasis,the T stages classification were T1-T2 in 17 cases and T3-T4 in 19 cases.While,10 cases with T1-T2 stage and 28 cases with T3-T4 stage were confirmed in the group with metastasis.There was no statistical significance of T stages and mean age in two groups （P〉0.05）.The level of cPSA in the serum was detected by chemiluminescent immunoassay,the level of tPSA,fPSA were detected by electro-chemiluminescent immunoassay,fPSA/tPSA,cPSA/tPSA were evaluated and the corresponding specificity were calculated.The correlation of age with tPSA,cPSA were analysed.The differences in PSA,fPSA/tPSA,cPSA/tPSA were compared between metastasis and non-metastasis group.ROC curve analysis was used to determine the diagnostic value of cPSA and tPSA,In the meantime,area of ROC curves were compared by Z test.Results The age was not related to the value of tPSA （r=-0.09,P=0.12） and cPSA（r=-0.38,P=0.14）.The median levels of tPSA,fPSA,and cPSA are 29.88μg/L,2.18 μg/L and 18.86 μg/L in the group without metastasis,respectively.The median levels of tPSA,fPSA,and cPSA were 410.05 μg/L,51.50 μ.g/L and 290.40 μg/L in the group with metastasis,respectively.Significant differences of those results could be found in two groups （P〈0.05）.fPSA/tPSA was 0.07 and cPSA/tPSA was 0.79 in the group without metastasis.fPSA/tPSA was 0.08 and cPSA/tPSA was 0.80 in the group of metastasis.fPSA/tPSA （P=0.77）,cPSA/tPSA （P=0.64） in patients with metastasis were not greater than in those without metastasis （P〉0.05）.The area under the curve of tPSA and cPSA were 0.83 （95% CI 0.73-0.93） and 0.82 （95%CI 0.73-0.92） respectively.Analysis of ROC curves showed that the AUC for cPSA is not significant different from tPSA （Z=1.64,P=0.10）.The specificity of cPSA was 22.2% which is higher than that of tPSA （19.4%） at a sensitivity of 92.1% in predicting metastasis comparing with the patients without metastasis.The sensitivity could reach to 90.0% when the cut off value of tPSA was 9μg/L or the cut off value of cPSA was 7 μg/L.Conclusions In our study,a preliminary validation that cPSA is useful for predicting the metastasis in patients with prostate cancer was made.