Chun Felix K-H, Haese Alexander, Ahyai Sascha A, Walz Jochen, Suardi Nazareno, Capitanio Umberto, Graefen Markus, Erbersdobler Andreas, Huland Hartwig, Karakiewicz Pierre I
Department of Urology, University of Hamburg, Hamburg, Germany.
Cancer. 2008 Aug 15;113(4):701-9. doi: 10.1002/cncr.23610.
Overtreatment of prostate cancer (PCa) is a concern, especially in patients who might qualify for the diagnosis of insignificant prostate cancer (IPCa). The ability to identify IPCa prior to definitive therapy was tested.
In a cohort of 1132 men a nomogram was developed to predict the probability of IPCa. Predictors consisted of prostate-specific antigen (PSA), clinical stage, biopsy Gleason sum, core cancer length and percentage of positive biopsy cores (percent positive cores). IPCa was defined as organ-confined PCa (OC) with tumor volume (TV) <0.5 cc and without Gleason 4 or 5 patterns. Finally, an external validation of the most accurate IPCa nomogram was performed in the same group.
IPCa was pathologically confirmed in 65 (5.7%) men. The 200 bootstrap-corrected predictive accuracy of the new nomogram was 90% versus 81% for the older nomogram. However, in cutoff-based analyses of patients who were qualified by our and the older nomograms as high probability for IPCa, respectively 63% and 45% harbored aggressive PCa variants at radical prostatectomy (Gleason score 7-10, ECE, SVI, and/or LNI).
Despite a high accuracy, currently available models for prediction of IPCa are incorrect in 10% to 20% of predictions. The rate of misclassification is even further inflated when specific cutoffs are used. As a consequence, extreme caution is advised when statistical tools are used to assign the diagnosis of IPCa.
前列腺癌（PCa）的过度治疗令人担忧，尤其是对于那些可能符合微小前列腺癌（IPCa）诊断标准的患者。我们测试了在确定性治疗前识别IPCa的能力。
在一个由1132名男性组成的队列中，开发了一种列线图来预测IPCa的概率。预测因素包括前列腺特异性抗原（PSA）、临床分期、活检Gleason评分总和、癌灶长度以及阳性活检核心的百分比（阳性核心百分比）。IPCa被定义为肿瘤体积（TV）<0.5 cc且无Gleason 4或5级模式的器官局限性PCa（OC）。最后，在同一组中对最准确的IPCa列线图进行了外部验证。
65名（5.7%）男性经病理证实为IPCa。新列线图经200次自展校正后的预测准确率为90%，而旧列线图为81%。然而，在基于截断值的分析中，分别有63%和45%经我们的列线图和旧列线图判定为IPCa高概率的患者，在根治性前列腺切除术中发现有侵袭性PCa变异（Gleason评分7 - 10分、包膜外侵犯、精囊侵犯和/或淋巴结转移）。
尽管预测准确率较高，但目前可用的IPCa预测模型在10%至20%的预测中是错误的。当使用特定截断值时，错误分类率甚至会进一步升高。因此，在使用统计工具进行IPCa诊断时，建议极度谨慎。
