Department of Urology, Vita-Salute University San Raffaele, Milan, Italy.
Eur Urol. 2010 Apr;57(4):551-8. doi: 10.1016/j.eururo.2009.12.023. Epub 2009 Dec 18.
Several guidelines have indicated that in patients with well-differentiated or moderately well-differentiated prostate cancer (PCa), a staging bone scan may be omitted. However, the guidelines recommendations have not yet been externally validated.
The aim of the study was to externally validate the available guidelines regarding the need for a staging bone scan in patients with newly diagnosed PCa. Moreover, we developed a novel risk stratification tool aimed at improving the accuracy of these guidelines.
DESIGN, SETTING, AND PARTICIPANTS: The study included 853 consecutive patients diagnosed with PCa between January 2003 and June 2008 at a single centre. All patients underwent bone scan using technetium Tc 99m methylene diphosphonate at diagnosis.
The area under the curve (AUC) of the criteria suggested by the guidelines (European Association of Urology, American Urological Association, National Comprehensive Cancer Network, and American Joint Committee on Cancer) to perform a baseline bone scan was assessed and compared with the accuracy of a classification and regression tree (CART) including prostate-specific antigen (PSA), clinical stage, and biopsy Gleason sum as covariates.
The AUC of the guidelines ranged between 79.7% and 82.6%. However, the novel CART model, which stratified patients into low risk (biopsy Gleason ≤7, cT1-T3, and PSA <10 ng/ml), intermediate risk (biopsy Gleason ≤7, cT2/T3, and PSA >10 ng/ml), and high risk (biopsy Gleason >7) was significantly more accurate (AUC: 88.0%) than all the guidelines (all p≤0.002). The limitation of this study resides in its retrospective design. Moreover, the proposed risk stratification tool can be considered only for patients who are candidates for radical prostatectomy until validated in other clinical settings.
This is the first study aimed at externally validating the available guidelines addressing the need for staging baseline bone scans in PCa patients. All guidelines showed high accuracy. However, their accuracy was significantly lower compared with the accuracy of the novel risk stratification tool. According to this tool, staging bone scans might be considered only for patients with a biopsy Gleason score >7 or with a PSA >10 ng/ml and palpable disease (cT2/T3) prior to treatment. However, before recommending its use in clinical practice, our model needs to be externally validated.
一些指南表明，对于分化良好或中度分化良好的前列腺癌（PCa）患者，可以省略分期骨扫描。然而，这些指南建议尚未经过外部验证。
本研究的目的是外部验证现有指南中关于新诊断 PCa 患者是否需要进行分期骨扫描的建议。此外，我们开发了一种新的风险分层工具，旨在提高这些指南的准确性。
设计、地点和参与者：这项研究纳入了 2003 年 1 月至 2008 年 6 月期间在单一中心接受诊断的 853 例连续 PCa 患者。所有患者在诊断时均使用锝 Tc 99m 亚甲基二膦酸盐进行骨扫描。
评估指南（欧洲泌尿外科学会、美国泌尿外科学会、国家综合癌症网络和美国联合委员会癌症）建议进行基线骨扫描的标准的曲线下面积（AUC），并将其与包括前列腺特异性抗原（PSA）、临床分期和活检 Gleason 总和作为协变量的分类回归树（CART）的准确性进行比较。
指南的 AUC 范围在 79.7%至 82.6%之间。然而，新型 CART 模型将患者分为低风险（活检 Gleason≤7、cT1-T3 和 PSA<10ng/ml）、中风险（活检 Gleason≤7、cT2/T3 和 PSA>10ng/ml）和高风险（活检 Gleason>7），其准确性明显高于所有指南（均 p≤0.002）。本研究的局限性在于其回顾性设计。此外，在其他临床环境中验证之前，该风险分层工具仅可用于候选根治性前列腺切除术的患者。
这是第一项旨在外部验证现有指南中关于 PCa 患者分期基线骨扫描需求的研究。所有指南都具有较高的准确性。然而，与新型风险分层工具的准确性相比，其准确性明显较低。根据该工具，仅在活检 Gleason 评分>7 或 PSA>10ng/ml 且有可触及疾病（cT2/T3）的患者，或在治疗前，才考虑进行分期骨扫描。然而，在推荐其在临床实践中使用之前，我们的模型需要进行外部验证。
