Schröder F H, van der Cruijsen-Koeter I, de Koning H J, Vis A N, Hoedemaeker R F, Kranse R
Department of Urology, Erasmus University and Academic Hospital, Rotterdam, The Netherlands.
J Urol. 2000 Mar;163(3):806-12.
At low prostate specific antigen (PSA) the indication for prostate biopsy is usually an abnormal digital rectal examination. We evaluate the diagnostic value of PSA, digital rectal examination, transrectal ultrasonography and tumor characteristics at low PSA (0 to 4.0 ng./ml.). We confirm and add to recent evidence that digital rectal examination has a low predictive value and that many significant cancers at this PSA range may be missed.
From 1994 to 1997 a total of 10,523 participants 54 to 74 years old were randomized to screening in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer. Of the participants 9,211 (87.5%) had PSA less than 4.0 ng./ml., and underwent digital rectal examination and transrectal ultrasonography. Expected rates of prostate cancer detection were calculated using logistic regression analysis. Radical prostatectomy was performed in about half of the 478 men diagnosed with prostate cancer. Tumors were characterized by pT category, Gleason score and cancer volume in 166 processed radical prostatectomy specimens. In 50 of these cases PSA was 0 to 4.0 ng./ml.
The positive predictive value of digital rectal examination and transrectal ultrasonography at PSA 0 to 4.0 ng./ml. was only 9.7%. Positive predictive value strongly depended on PSA. Sensitivity was calculated by using estimates of the prevalence of sextant biopsy detectable prostate cancers. Of 760 detectable cancers 478 (67%) were diagnosed irrespective of PSA in men screened with digital rectal examination, transrectal ultrasonography and PSA. Only 127 of 348 detectable prostate cancers (36.5%) were actually diagnosed in men with PSA 2 to 4 mg./ml. The importance of these missed cancers was evaluated with parameters of tumor aggressiveness within PSA ranges.
Approximately half of the tumors missed with PSA 0 to 4 ng./ml. had aggressive characteristics (Gleason score 7 or greater, Gleason 4-5 components) and were organ confined. These tumors should be diagnosed and treated according to the present understanding of their natural history. More sensitive and selective screening strategies are needed. Presently a wrong "window of opportunity" is used for early detection of prostate cancer.
在前列腺特异性抗原（PSA）水平较低时，前列腺活检的指征通常是直肠指检异常。我们评估了PSA、直肠指检、经直肠超声检查以及低PSA水平（0至4.0 ng/ml）时肿瘤特征的诊断价值。我们证实并补充了近期的证据，即直肠指检的预测价值较低，在此PSA范围内许多显著的癌症可能会被漏诊。
1994年至1997年，共有10523名年龄在54至74岁的参与者被随机分配至欧洲前列腺癌筛查随机研究鹿特丹分部进行筛查。其中9211名（87.5%）参与者的PSA低于4.0 ng/ml，并接受了直肠指检和经直肠超声检查。使用逻辑回归分析计算前列腺癌的预期检出率。在478名被诊断为前列腺癌的男性中，约一半接受了根治性前列腺切除术。对166份处理过的根治性前列腺切除标本中的肿瘤进行了pT分类、Gleason评分和癌体积特征分析。其中50例患者的PSA为0至4.0 ng/ml。
PSA在0至4.0 ng/ml时，直肠指检和经直肠超声检查的阳性预测值仅为9.7%。阳性预测值强烈依赖于PSA。通过使用六分区活检可检测前列腺癌患病率的估计值来计算敏感性。在760例可检测到的癌症中，478例（67%）通过直肠指检、经直肠超声检查和PSA筛查的男性被诊断出来，与PSA水平无关。在PSA为2至4 ng/ml的男性中，348例可检测到的前列腺癌中只有127例（36.5%）实际被诊断出来。通过PSA范围内肿瘤侵袭性参数评估这些漏诊癌症的重要性。
PSA在0至4 ng/ml时漏诊的肿瘤中，约一半具有侵袭性特征（Gleason评分7分或更高，Gleason 4-5成分）且局限于器官内。应根据目前对其自然史的理解对这些肿瘤进行诊断和治疗。需要更敏感和更具选择性的筛查策略。目前用于前列腺癌早期检测的“机会窗口”有误。
