前列腺特异性抗原和Gleason评分对前列腺癌患者核素骨扫描结果的预测价值

Predictive value of prostate-specific antigen and Gleason sum for results of radionuclide bone scintigraphy in patients with prostate cancer

目的:探讨前列腺癌患者前列腺特异性抗原(prostate-specific antigen,PSA)水平以及穿刺病理Gleason评分对核素骨扫描结果的预测价值,以确定对中国前列腺癌初诊患者进行核素骨扫描检查的恰当时机。方法:对1994年1月至2005年12月间在北京大学第一医院泌尿外科住院治疗的624例经病理检查确诊为前列腺癌的患者资料进行回顾性分析,评价血清总PSA(total prostate specific antigen,tPSA)、前列腺病理检查Gleason评分与骨扫描结果的相关性。结合临床实际情况分析受试者工作特征(receiver operating characteristics,ROC)曲线,确定选择进行骨扫描检查的PSA和Gleason评分界值。结果:624例前列腺癌患者中,有443例同时进行了骨扫描检查和血清PSA测定,其中骨扫描阳性患者216例(48.8%);338例同时具有骨扫描、PSA和前列腺病理检查Gleason评分。骨扫描阳性前列腺癌患者的tPSA水平(中位值71.00μg/L,范围1.30～2 400.00μg/L)显著高于骨扫描阴性患者(中位值60.00μg/L,范围0.60～201.00μg/L,秩和检验P<0.001),骨扫描阳性患者的Gleason评分(7.7±1.5)也显著高于骨扫描阴性患者(6.7±1.8,P<0.001)。回归分析显示PSA及Gleason评分分别与骨扫描检查结果具有明显的正相关性(lg[PSA]:r=0.933,B=0.352,P=0.001;Gleason评分:r=0.971,B=0.096,P<0.001)。tPSA<10μg/L时骨扫描阳性率为<9.0%,Gleason评分<5时骨扫描阳性率为3.8%。tPSA>15μg/L或Gleason评分≥7时,对骨扫描阳性结果的预测灵敏度、特异度、阳性预测值、阴性预测值和诊断准确度分别为97.5%、24.7%、54.4%、91.5%和60.0%。结论:前列腺癌患者的骨扫描阳性结果与较高的血清tPSA水平和病理检查Gleason评分具有显著的正相关性,建议tPSA<10μg/L和Gleason评分<5的新诊断前列腺癌患者可不进行骨扫描,tPSA>15μg/L或Gleason评分≥7的前列腺癌患者应该进行骨扫描检查。

Objective： To investigate the predictive value of prostate-specific antigen （PSA） and Gleason sum for results of radionuclide bone scintigraphy in prostate cancer patients, in order to deter- mine when to perform a radionuclide bone scintigraphy in Chinese patients with newly diagnosed prostate cancer. Methods： We retrospectively reviewed the charts of 624 consecutive patients with a pathology diagnosis of prostate cancer hospitalized in Department of Urology, Peking University First Hospital between Jan. 1994 and Dec. 2005, and evaluated the relationships between results of bone scintigraphy and serum tPSA, and between bone scintigraphy and Gleason sum. The receiver operating characteristics （ROC） curves were analyzed to determine the cut-off values of tPSA and Gleason sum for predicting positive results of bone seintigraphy. Results： In the study, 443 patients underwent both a radionuclide bone scan and a serum PSA test prior to treatment, of whom, 216 （48.8%） got positive results, and 338 also possessed the Gleason sum for pathological evaluation. The serum tPSA levels were significantly higher in patients with positive results of the bone scan （ median： 71.00 ug/L; range： 1.30 -2 400.00 ug/L） than those with negative results （ median： 60.00 ug/L; range： 0.60 - 201.00 ug/L; rank P 〈 0. 001 ）, and the Gleason sums were also significantly higher in positive-bone-scan patients than in nega- tive-bone-scan patients （7.7 ± 1.5 vs. 6.7 ± 1.8, P 〈0.001 ）. Linear regression analysis suggested significant positive correlation between the results of the bone scan and the two afore-mentioned parameters, respectively （ lg[ PSA ] ： r = 0. 933, B = 0.352, P = 0.001 ; Gleason sum ： r = 0.971, B = 0.096, P 〈 0. 001 ）. The incidence of a positive bone scan result was 9.0% in patients with tPSA 〈 10 ug/L and 3.8% in patients with Gleason sum 〈 5. When the indication for bone scan was established as tPSA 〉 15 ug/L or Gleason sum≥7,its sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for positive results were 97.5%, 24.7%, 54.4%, 91.5% and 60.0%, respectively. Conclusion ： In patients with prostate cancer, their positive results of the bone scan are significantly positively correlated to their higher PSA levels and higher Gleason sums, respectively. Our analyses suggest that a patient with newly diagnosed prostate cancer would not need to undergo radionuclide bone scintigraphy when the PSA level is lower than 10 ug/L and Gleason sum is less than 5, and that a prostate cancer patient with tPSA 〉 15 ug/L or Gleason sum ≥7 should take a bone scintigraphy.