血清/尿PSA比值对血清PSA处于“灰区”中前列腺癌的诊断价值

The role of the ratio of serum PSA and urine PSA in diagnosing prostate carcinoma within the serum PSA "gray" zone

目的探讨血清前列腺特异性抗原(sPSA)与尿前列腺特异性抗原(uPSA)比值(s/uPSA)对血清PSA处于诊断"灰区"——sPSA于4.0～10.0ng/ml(放射免疫法范围)前列腺癌的诊断价值。方法选择血清PSA(sPSA)于诊断"灰区"的共191例前列腺疾病患者,采用放射免疫方法检测其尿PSA(uPSA)水平,根据前列腺活检结果分为前列腺癌组(PCa组,n=76)和良性前列腺增生症组(BPH组,n=115),比较两组s/uPSA比值以及两组间sPSA和s/uPSA比值的受试者运算特性曲线(ROC)面积。结果BPH组与PCa组的sPSA分别为(5.20±1.09)ng/ml和(6.41±2.12)ng/ml,uPSA分别(3.57±0.97)ng/ml和(2.17±0.61)ng/ml,sPSA和uPSA在BPH组与PCa组两者间差别均无统计学意义(t=0.91,t=1.24,P>0.05);BPH组与PCa组的s/uPSA分别为(2.32±0.61)和(4.13±1.09),PCa组s/uPSA比值明显高于BPH组,差别具有统计学意义(t=4.17,P<0.01)。s/uPSA比值和sPSA的ROC曲线下面积分别为0.836和0.703。在保持95%敏感性时,s/uPSA比值和sPSA的特异性分别为77.1%和39.6%。结论在血清PSA值4.0～10.0ng/ml范围内,s/uPSA比值较sPSA更好地检出前列腺癌;在保持同一敏感性时,s/uPSA较sPSA具有更高的特异性。

Objective To evaluate the value of serum and urine prostate specific antigen ratio （s/u PSA）in diagnosing patients with prostate carcinoma （PCa） whose serum PSA （sPSA） concentration is between 4.0 ng/ml and 10.0ng/ml. Methods A total of 191 consecutive patients with prostate diseases whose sPSA concentration ranged from 4.0 ng/ml to 10.0ng/ml were accessed. The sPSA and uPSA concentration of all patients was analyzed by radioimmunologic assay and the s/u PSA ratios were calculated. According to the results of prostate biopsy, the patients were divided into two groups： PCa group （n=76） and benign prostate hyperplasia （BPH） group （n=115）. The receiver operating characteristic （ROC） curves were generated by plotting the sensitivity versus specificity. Area under the cures was calculated for each assay. Results There was no statistically significant difference in both sPSA and uPSA levels between BPH group and PCa group （5.20±1.09ng/ml vs 6.41±2.12ng/ml; 3.57±0.97 ng/ml vs 2.17±0.61 ng/ml respectively ）（t=0.91, t= 1.24, P〉0.05, respectively）. However, the s/u PSA ratios in PCa group were higher than those in BPH group （4.13±1.09 vs 2.32±0.61, t=4.17, P〈0.01）. Area under the ROC curves of s/u PSA ratio and sPSA were 0.836 and 0.703 respectively. The specificity of s/u PSA ratio and sPSA were 77.1% and 39.6% respectively at cutoffs yielding 95% sensitivity. Conclusions The s/u PSA ratio can provide better differential effect of PCa and BPH than traditional sPSA when sPSA concentration ranges from 4.0 ng/ml to 10.0ng/ ml. At the same sensitivity, s/u PSA has a higher specificity than sPSA.