Catalona W J, Richie J P, deKernion J B, Ahmann F R, Ratliff T L, Dalkin B L, Kavoussi L R, MacFarlane M T, Southwick P C
Division of Urologic Surgery, Washington University School of Medicine, St. Louis, Missouri.
J Urol. 1994 Dec;152(6 Pt 1):2031-6. doi: 10.1016/s0022-5347(17)32299-1.
We present the results of a prospective multicenter clinical trial of nearly 5,000 men in which prostate specific antigen (PSA) density was compared to the serum PSA concentration alone for early detection of prostate cancer. All men were evaluated with PSA and digital rectal examination. If PSA was elevated (greater than 4 ng./ml., Hybritech Tandem assay) or digital rectal examination was suspicious, transrectal ultrasound guided biopsies were recommended. Prostate volume was estimated by transrectal ultrasound measurements using a prolate ellipse volume calculation and PSA density was calculated by dividing serum PSA concentration by gland volume. Using a PSA density cutoff of 0.15 as recommended in the literature enhanced specificity but at the cost of missing half of the tumors. Of the organ confined neoplasms 47% were detected by a PSA of greater than 4.0 ng./ml. but they were missed by a PSA density of more than 0.15. PSA density may not be predictive for cancer because accurate estimation of transrectal ultrasound volume is difficult (r = 0.61 for estimated transrectal ultrasound volume versus pathological prostate weight). However, a relationship does exist among transrectal ultrasound volume, PSA and positive predictive value for cancer. PSA concentrations of less than 4.0 ng./ml. did not indicate a need for biopsy (positive predictive value 12 to 17%) unless the digital rectal examination findings were suspicious for cancer. A high percentage of patients with a PSA of more than 10 ng./ml. had cancer (30 to 75%), regardless of gland size. Patients with intermediate PSA concentrations (4.1 to 9.9 ng./ml.) and a gland size of 50 cc or less had a 35 to 51% positive predictive value, while those with intermediate PSA concentrations and a large gland (more than 50 cc) had a 15% positive predictive value. We conclude that in men with a PSA level of 4.1 to 9.9 ng./ml., and normal digital rectal examination and transrectal ultrasound findings, the use of a PSA density cutoff of more than 0.15 for biopsy results in half of the tumors being missed. Thus, we recommend that men in this group undergo biopsy based upon serum PSA concentration rather than PSA density.
我们公布了一项针对近5000名男性的前瞻性多中心临床试验结果，该试验比较了前列腺特异性抗原（PSA）密度与单独的血清PSA浓度用于早期检测前列腺癌的情况。所有男性均接受了PSA检测和直肠指检。如果PSA升高（大于4 ng/ml，Hybritech Tandem检测法）或直肠指检可疑，则建议进行经直肠超声引导下活检。通过经直肠超声测量，采用长椭圆体体积计算公式估算前列腺体积，并通过将血清PSA浓度除以腺体体积来计算PSA密度。按照文献推荐，使用0.15的PSA密度临界值可提高特异性，但代价是漏诊了一半的肿瘤。在局限性肿瘤中，47%可通过PSA大于4.0 ng/ml检测到，但却会被PSA密度大于0.15漏诊。PSA密度可能无法预测癌症，因为经直肠超声体积的准确估算很困难（经直肠超声估算体积与前列腺病理重量的r值为0.61）。然而，经直肠超声体积、PSA与癌症阳性预测值之间确实存在关联。PSA浓度小于4.0 ng/ml时，除非直肠指检结果可疑有癌症，否则无需进行活检（阳性预测值为12%至17%）。PSA大于10 ng/ml的患者中，无论腺体大小，患癌比例都很高（30%至75%）。PSA浓度处于中等水平（4.1至9.9 ng/ml）且腺体大小为50 cc或更小的患者，阳性预测值为35%至51%，而PSA浓度中等且腺体较大（大于50 cc）的患者，阳性预测值为15%。我们得出结论，对于PSA水平在4.1至9.9 ng/ml、直肠指检和经直肠超声检查结果正常的男性，使用大于0.15的PSA密度临界值进行活检会导致一半的肿瘤被漏诊。因此，我们建议该组男性根据血清PSA浓度而非PSA密度进行活检。
