*Department of Urology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, Japan.
Jpn J Clin Oncol. 2013 Dec;43(12):1255-60. doi: 10.1093/jjco/hyt154. Epub 2013 Oct 21.
Preoperative nomograms can accurately predict the rate of biochemical recurrence after radical prostatectomy. Although these nomograms were shown to be valid in several external validation cohorts of Caucasian patients, they have not been validated in non-Caucasian patients from Asian countries. We therefore validated these preoperative nomograms in a Japanese cohort, using different cutoff values of prostate-specific antigen concentrations for biochemical recurrence.
We analyzed 637 patients who underwent radical prostatectomy for clinically localized prostate cancer at the Tokyo Medical University Hospital between February 2000 and January 2011. We evaluated two prostate-specific antigen cutoff values for biochemical recurrence, 0.2 and 0.4 ng/ml. Using c-index and calibration plots, we validated the previously developed Kattan and Stephenson nomograms.
Overall, the mean 5-year non-biochemical recurrence rate was 72 ± 4%. Using a prostate-specific antigen cutoff values of 0.2 and 0.4 ng/ml, the c-indices for the Kattan nomogram were 0.714 and 0.733. Similarly, using a prostate-specific antigen cutoff values of 0.2 and 0.4 ng/ml, the c-indices for the Stephenson nomograms were 0.717 and 0.671. The calibration plots showed that the predictive value of the Stephenson nomogram at a prostate-specific antigen cutoff of 0.2 ng/ml was close to the actual outcomes compared with other combinations of nomograms and prostate-specific antigen cutoff levels.
Because the c-indices of both nomograms were generally high, these nomograms can be applied to our cohort. The addition of biopsy information did not markedly improve the c-index but resulted in good calibration, indicating that the Stephenson nomogram may be a better fit for our patient cohort.
术前列腺癌特异性抗原（PSA）nomogram 可准确预测根治性前列腺切除术（RP）后生化复发率。虽然这些 nomogram 在多个白人患者的外部验证队列中得到验证，但它们在亚洲非白人患者中尚未得到验证。因此，我们使用不同的 PSA 浓度作为生化复发的截点值，在日本队列中对这些术前 nomogram 进行了验证。
我们分析了 2000 年 2 月至 2011 年 1 月期间在东京医科大学医院接受局限性前列腺癌 RP 的 637 例患者。我们评估了生化复发的两个 PSA 截断值，即 0.2 和 0.4ng/ml。使用 c-index 和校准图，对 Kattan 和 Stephenson nomogram 进行了验证。
总体而言，5 年无生化复发率为 72±4%。使用 PSA 截断值 0.2 和 0.4ng/ml，Kattan nomogram 的 c-index 分别为 0.714 和 0.733。同样，使用 PSA 截断值 0.2 和 0.4ng/ml，Stephenson nomogram 的 c-index 分别为 0.717 和 0.671。校准图显示，与其他 nomogram 和 PSA 截断值组合相比，当 PSA 截断值为 0.2ng/ml 时，Stephenson nomogram 的预测值更接近实际结果。
由于这两个 nomogram 的 c-index 通常较高，因此可以将这些 nomogram 应用于我们的队列。增加活检信息并没有显著提高 c-index，但却实现了良好的校准，表明 Stephenson nomogram 可能更适合我们的患者队列。
