Urology Unit, Division of Surgery, Repatriation General Hospital, Daw Park, SA, Australia.
BJU Int. 2011 Nov;108 Suppl 2:51-6. doi: 10.1111/j.1464-410X.2011.10687.x.
What's known on the subject? and What does the study add? Prognostic tools, such as the Cancer of the Prostate Risk Assessment (CAPRA) score and the 1998 Kattan and 2006 Stephenson nomograms, predicting biochemical recurrence after radical prostatectomy are widely used for treatment decision making and counselling patients. However, tools derived in certain cohorts tend to perform less well when they are applied to populations that are dissimilar in terms of population or disease characteristics, health systems or treatment practices. Some of the loss in accuracy of a prognostic tool is a consequence of unknown factors and hence the performance of a tool when applied to a different population is unknown and largely unpredictable. This study validates these widely used tools in South Australian patients treated at three public hospitals. All three tools discriminated well according to risk of recurrence in these patients. However, when compared against observed rates of recurrence, it was found that predictions of recurrence varied widely between the three tools, suggesting that their use in counselling patients on such risk may not be appropriate. Interestingly, the oldest of the three tools (Kattan 1998) was the best predictor of absolute risk of recurrence. In the paper, this is linked to later adoption of updated Gleason grading, among other factors.
In many countries, prognostic tools, which draw on the experience of thousands of patients with cancer, are used to predict cancer outcomes, but accuracy varies. This paper compares the accuracy of three widely used tools predicting prostate cancer recurrence after surgery in Australian patients. The results show that all tools were good at predicting which patients were most likely to experience recurrence and which were least. However, prediction of absolute risk varied and the oldest tool was the most accurate.
• To compare performance of the CAPRA score and two commonly used risk assessment nomograms, the 1998 Kattan and the 2006 Stephenson, in an untested Australian cohort.
• We present data on 635 men from the South Australian Prostate Cancer Clinical Outcomes Database who underwent radical prostatectomy between January 1996 and May 2009 and had all required variables for predicting biochemical recurrence (BCR). • BCR was defined as prostate-specific antigen ≥ 0.2 ng/mL or secondary treatment for a rising prostate-specific antigen. • Accuracy was evaluated using Harrell's concordance index, plotting calibration curves, and constructing decision analysis curves.
• Concordance indices were high for all three tools: 0.791, 0.787 and 0.744 for the 2006 Stephenson nomogram, CAPRA score and 1998 Kattan nomogram respectively. • At 3 years, calibration of the tools (agreement between predicted and observed BCR-free probability) was close to ideal for the 1998 Kattan nomogram, whereas the 2006 Stephenson model underestimated and the CAPRA model overestimated BCR-free probability. • The 1998 Kattan and 2005 CAPRA tools performed better than the 2006 Stephenson nomogram across a wide range of threshold probabilities using decision curve analysis.
• All three tools discriminate between patients' risk effectively. • Absolute estimates of risk are likely to vary widely between tools, however, suggesting that models should be validated and, if necessary, recalibrated in the population to which they will be applied. • Recent development does not mean a nomogram is more accurate for use in a particular population.
用于预测根治性前列腺切除术后生化复发的预后工具，如前列腺癌风险评估 (CAPRA) 评分和 1998 年的 Kattan 和 2006 年的 Stephenson 列线图，已广泛用于治疗决策和为患者提供咨询。然而，在应用于人口特征、卫生系统或治疗实践存在差异的人群时，某些队列中得出的工具往往表现不佳。预后工具准确性的部分损失是由于未知因素造成的，因此在不同人群中应用工具的性能是未知的，且在很大程度上是不可预测的。本研究在南澳大利亚的三家公立医院中对这些广泛使用的工具进行了验证。所有三种工具在这些患者中均能很好地区分复发风险。然而，与观察到的复发率相比，发现三种工具的预测结果差异很大，这表明它们在为患者提供此类风险咨询方面可能不适用。有趣的是，三种工具中最古老的工具（Kattan 1998 年）是预测复发绝对风险的最佳工具。在本文中，这与后来采用更新的 Gleason 分级等因素有关。
在许多国家，利用数千名癌症患者的经验得出的预后工具被用于预测癌症结局，但准确性存在差异。本文比较了三种广泛用于预测澳大利亚患者手术后前列腺癌复发的工具的准确性。结果表明，所有工具都能很好地预测哪些患者最有可能经历复发，哪些患者最不可能经历复发。然而，绝对风险的预测存在差异，且最古老的工具最准确。
• 比较 CAPRA 评分和两种常用风险评估列线图，即 1998 年的 Kattan 和 2006 年的 Stephenson，在未经测试的澳大利亚队列中的性能。
• 我们介绍了南澳大利亚前列腺癌临床结局数据库中 635 名接受根治性前列腺切除术的男性的数据，这些患者于 1996 年 1 月至 2009 年 5 月期间接受手术治疗，并且所有变量都可用于预测生化复发 (BCR)。• BCR 定义为前列腺特异性抗原（PSA）≥0.2ng/ml 或因 PSA 升高而进行的二线治疗。• 采用 Harrell 一致性指数、绘制校准曲线和构建决策分析曲线来评估准确性。
• 三种工具的一致性指数均较高：2006 年 Stephenson 列线图、CAPRA 评分和 1998 年 Kattan 列线图的分别为 0.791、0.787 和 0.744。• 在 3 年时，这些工具的校准（预测和观察到的无 BCR 概率之间的一致性）接近理想状态，1998 年 Kattan 列线图接近理想状态，而 2006 年 Stephenson 模型低估了无 BCR 概率，CAPRA 模型高估了无 BCR 概率。• 使用决策曲线分析，1998 年 Kattan 和 2005 年 CAPRA 工具在广泛的阈值概率范围内优于 2006 年 Stephenson 列线图。
• 所有三种工具都能有效地区分患者的风险。• 然而，绝对风险估计值在工具之间可能存在很大差异，这表明模型应在应用于特定人群时进行验证和（如有必要）重新校准。• 最近的发展并不意味着列线图在特定人群中更准确。
