Scheerer J, Kahabka P, Altwein J E, Weißbach L
AstraZeneca GmbH, Wedel, Germany. joachim.scheerer @ astrazeneca.com
Urol Int. 2012;89(2):155-61. doi: 10.1159/000339604. Epub 2012 Jul 19.
The numbers needed to treat (NNT) and the corresponding confidence intervals for patients with prostate cancer and defined annual PSA increases (PSA velocity, PSAV) have not been described previously.
The objective of this study is to assess NNT, numbers needed to treat to harm and corresponding confidence intervals for radical prostatectomy (RP) in patients with prostate cancer defined as a PSAV ≤2 ng/ml/year.
NNT following RP were estimated in risk groups defined by PSAV using mortality statistics and hazard ratios obtained in a noncontrolled trial. As no suited control group and no appropriate randomized trials were available for doing this calculation and as such trials are unlikely to become available in the near future we have calculated our NNTs as published previously by using relative risk reduction from an earlier randomized trial (RCT) comparing RP with watchful waiting (WW) [Can J Urol 2006;13(suppl 1):48-55].
For preoperative PSAV >2 ng/ml/year, NNT for RP were estimated at 25, whereas for preoperative PSAV ≤2 ng/ml/year, the estimate was 618. The lower 95% confidence limits (NNTBl) were 9 and 126, respectively (treatment with benefit). The implications emerging from these findings are discussed by comparison with published NNT values from other RCTs. The lower 95% confidence limit for preoperative PSAV ≤2 ng/ml/year was found to be large in comparison.
The NNT estimate obtained here for PSAV >2 ng/ml/year and its lower 95% confidence interval is comparable to values in other studies on prostate cancer for therapies considered to be effective, while the estimated NNT for patients with PSAV ≤2 ng/ml/year is large in comparison. We conclude that the benefits of RP for localized prostate cancer with preoperative PSAV ≤2 ng/ml/year may be considered small. There are several limitations to our findings, the most important of which lies in the fact that while PSAV remains significantly associated with outcomes, the predictive value of PSA measurements is low. While PSAV >2 ng/ml/year clearly indicates a need for surgery, a PSAV ≤2 ng/ml/year should imply further decision making.
既往尚未描述前列腺癌患者的治疗所需人数（NNT）以及与特定年度前列腺特异抗原（PSA）升高（PSA速度，PSAV）相对应的置信区间。
本研究的目的是评估前列腺癌患者中，PSAV≤2 ng/ml/年时，根治性前列腺切除术（RP）的NNT、造成伤害所需治疗人数以及相应的置信区间。
使用死亡率统计数据和在一项非对照试验中获得的风险比，在由PSAV定义的风险组中估计RP后的NNT。由于没有合适的对照组且没有合适的随机试验可用于此计算，并且此类试验在近期不太可能出现，因此我们按照先前发表的方法，通过使用一项比较RP与观察等待（WW）的早期随机试验（RCT）中的相对危险度降低来计算我们的NNT[《加拿大泌尿外科杂志》2006年；13（增刊1）：48 - 55]。
对于术前PSAV>2 ng/ml/年，RP的NNT估计为25，而对于术前PSAV≤2 ng/ml/年，估计为618。较低的95%置信下限（NNTBl）分别为9和126（有益治疗）。通过与其他RCT发表的NNT值进行比较，讨论了这些发现所产生的影响。结果发现，术前PSAV≤2 ng/ml/年的较低95%置信下限相比之下较大。
此处获得的PSAV>2 ng/ml/年的NNT估计值及其较低的95%置信区间与其他关于前列腺癌的有效治疗研究中的值相当，而PSAV≤2 ng/ml/年患者的估计NNT相比之下较大。我们得出结论，对于术前PSAV≤2 ng/ml/年的局限性前列腺癌，RP的益处可能较小。我们的研究结果存在若干局限性，其中最重要的是，虽然PSAV仍然与结局显著相关，但PSA测量的预测价值较低。虽然PSAV>2 ng/ml/年明确表明需要手术，但PSAV≤2 ng/ml/年则应意味着需要进一步决策。
