血清前列腺特异性抗原同源异构体2在前列腺癌诊断中的应用价值

Clinical performance of serum proprostate-specific antigen isoform [ -2 ] proPSA in prostate cancer

目的探讨血清PSA低水平增高病例中，前列腺特异性抗原同源异构体2（p2PSA）、百分p2PSA（％p2PSA）和前列腺健康指数（PHI）在前列腺癌中的应用价值。方法病例对照研究。收集2014年3至10月在北京大学第一医院就诊的男性患者中总PSA（tPSA）结果在4．0—20．0μg／L之间，并接受了经直肠超声引导前列腺穿刺活检患者的血清和临床资料。其中54例前列腺癌，86例非前列腺癌人群。按照tPSA水平将病例分为tPSA4．0～10．0Ixg／L和tPSAl0．1—20．0Ixg／L两组，以病理结果为金标准，MedCalcvet6统计软件进行统计分析，采用ROC曲线比较各标志物在前列腺癌中的诊断效能。结果tPSA水平4．0～10．0μg／L组中，前列腺癌组和非前列腺癌组患者仅％p2PSA、PHI差异具有统计学意义[％p2PSA：1．94（1．42～2．80）VS．1．22（1．03—1．64），Z=3．612，P〈0．01；PHI：49．80（37．60～75．00）VS．33．70（25．53～42．35），Z=3．722，P〈0．01]；％p2PSA和PHI在前列腺癌诊断中具有较高准确性，AUC分别为0．709和0．716，大于f／tPSA（AUC0．587），但差异无统计学意义，P值分别为0．093、0．071。tPSA水平10．1～20．0Ixg／L组中，前列腺癌组和非前列腺癌组患者仅p2PSA、％p2PSA、PHI差异具有统计学意义[p2PSA：32．05（23．10～56．20）ng／LVS．21．80（14．85～31．48）ng／L，Z=5．183，P〈0．05；％p2PSA：2．40（1．95～2．77）VS．1．13（0．93—1．24），Z=17．854，P〈0．01；PHI：92．60（70．50～110．50）vs．45．50（39．50～51．52），Z=15．764，P〈0．01]；p2PSA、％p2PSA和PHI均对前列腺癌诊断具有较高的准确性，AUC分别为0．735、0．936和0．910，与f／tPSA相比（AUC0．579），差异具有统计学意义，P值分别为0．043、0．001、0．002。结论在血清PSA低水平增高病例中，与经典指标tPSA和f/tPSA相比，p2PSA及相关指标％p2PSA和PHI具有更高的肿瘤特异性，能提高前列腺癌诊断的准确性，将可能成为更好的前列腺癌辅助诊断新指标。

Objective To evaluate the application value of isoform [-2 ] proprostate-specific antigen （p2PSA） ,percentage of p2PSA （% p2PSA） and prostate health index （PHI） in cases with slightly elevated serum PSA. Methods A case-control study was adopted. The clinical data and sera of patients who had total PSA （tPSA） values of 4. 0 -20. 0μg/L and received transrectal ultrasound-guided prostate biopsy were collected. There were 54 cases of prostate cancer and 86 cases of non-prostate cancer groups recruited. According to the level of tPSA, the patients were divided into two groups ： tPSA levels ranged from 4.0 - 10. 0 μg/L and tPSA levels ranged from 10. 1 - 20. 0μg/L. The results were analyzed with MedCalc vet 6 statistical software. Adopting pathological results as gold standard for the diagnosis of prostate cancer, receiver operating curve （ROC） was depicted to evaluate the diagnostic efficiency of all the serum markers for prostate cancer. Results In the group of tPSA levels ranged from 4. 0 - 10. 0 μg/L, the levels of % p2PSA and PHI were significantly different [ % p2PSA ： 1.94 （ 1.42 - 2.80） vs. 1.22 （ 1.03 - 1.64）, Z = 3.612,P〈0.01;PHI：49.80（37.60-75.00） vs. 33.70（25.53-42.35） ,2=3.722, P〈0.01].The % p2PSA and PHI had higher diagnostic accuracy for prostate cancer. The areas under curve （AUC） were 0. 709 and 0. 716, respectively, which were higher than the AUC of f/tPSA （0. 587） but of no statistical significance （P values were 0. 093 and 0. 071, respectively）. In the group of tPSA levels ranged from 10. 1 -20. 0μg/L, the levels of p2PSA, % p2PSA and PHI were significantly different[ p2PSA：32.05（23.10 - 56.20） ng/L vs. 21.80 （ 14.85 - 31.48 ） ng/L, Z = 5.183, P 〈 0.05 ; % p2PSA ：2.40 （ 1.95 - 2.77 ） vs. 1. 13（0.93 - 1.24） ,Z = 17. 854,P 〈0.01 ;PHI：92.6（70.50 - 110.50） vs. 45.5（39.50 -51.52） ,Z = 15. 764,P 〈0.011- p2PSA, % p2PSA and PHI had higher diagnostic accuracy for prostate cancer. The areas under curve （AUC） were 0. 735, 0. 936 and 0. 910, respectively, which were significantly higher than the AUC of f/tPSA （ 0.579 ） （ P values were 0.043, 0.001 and 0.002, respectively） . Conclusion Compared with the classic indicators of tPSA and f/tPSA, p2PSA and related indicators, % p2PSA and PHI, had higher specificity and diagnostic accuracy for prostate cancer, and may have the potential to help the diagnosis of prostate cancer.