JNCI：PSA筛查并不能预测前列腺癌特异性死亡事件的发生

筛查组和对照组患者前列腺癌特异性死亡事件

欧洲前列腺癌随机筛查研究（ERSPC）结果提示应用前列腺特异性抗原对前列腺癌进行筛查能降低前列腺癌的死亡率。来自芬兰Tampere大学的Tuomas P等评估了芬兰前列腺癌筛查研究（ERSPC的最大的组成部分）中死亡率的相关的结果。本研究的主要终点事件为前列腺癌特异性死亡率。他们的研究结果发表在JNCI 3月的在线期刊上。
研究者从登记在册的人口中共纳入了80144名男性，他们被随机分为2组，一组为筛查组（SA），另一组为对照组（CA）。在筛查组的受试者每隔4年进行一次PSA筛查，共进行3次测定，如果其PSA浓度大于等于4.0ng/mL或PSA浓度介于3.0至3.9ng/mL但游离PSA/总PSA小于等于16%的话，那么研究者建议其进行前列腺活检。在研究中，研究者对所有入组的受试者都进行了为期长达12年的随访。研究者采用Cox风险比例模型估计了前列腺癌发病率和死亡率的风险比。所有的统计检验都在双侧进行。
前列腺癌的发病率在筛查组中为8.8/1000人-年，在对照组则为6.6/1000人-年，风险比为1.34，95%可信区间为1.27至1.40。与对照组相比，筛查组的晚期前列腺癌发病率更低，两组分别为1.6和1.2，风险比为0.73，两组差异具有显著统计学意义。研究者需要就1199人进行筛查且在其中发现25例前列腺癌患者才能避免1例前列腺癌特异性死亡事件。研究者没有观察到所有原因造成的死亡率在两组中存在差异。
本研究结果提示，在第12年时，一项相对保守的筛查方案仅能带来前列腺癌特异性死亡率的微弱及不具统计学显著意义的降低，但是其所付出的代价则是对患者的过度诊断。
与前列腺癌相关的拓展阅读：

• 地加瑞克治疗前列腺癌疗效佳
• NEJM：间歇性雄激素剥夺治疗可小幅改善前列腺癌患者生存质量
• 地加瑞克治疗前列腺癌疗效佳
• Lancet Oncol：经皮雌激素治疗前列腺癌可减少并发症的发生
• 短期雄激素阻断治疗高危前列腺癌安全有效
• NEJM：前列腺癌手术后15年功能结局与放疗相似 更多信息请点击：有关前列腺癌更多资讯

Prostate Cancer Mortality in the Finnish Randomized Screening Trial.
Background
Prostate cancer (PC) screening with prostate-specific antigen (PSA) has been shown to decrease PC mortality by the European Randomized Study of Screening for Prostate Cancer (ERSPC). We evaluated mortality results in the Finnish Prostate Cancer Screening Trial, the largest component of ERSPC. The primary endpoint was PC-specific mortality.
Methods
A total of 80 144 men were identified from the population registry and randomized to either a screening arm (SA) or a control arm (CA). Men in the SA were invited to serum PSA determination up to three times with a 4-year interval between each scan and referred to biopsy if the PSA concentration was greater than or equal to 4.0ng/mL or 3.0 to 3.99ng/mL with a free/total PSA ratio less than or equal to 16%. Men in the CA received usual care. The analysis covers follow-up to 12 years from randomization for all men. Hazard ratios (HRs) were estimated for incidence and mortality using Cox proportional hazard model. All statistical tests were two-sided.
Results
PC incidence was 8.8 per 1000 person-years in the SA and 6.6 in the CA (HR = 1.34, 95% confidence interval [CI] = 1.27 to 1.40). The incidence of advanced PC was lower in the SA vs CA arm (1.2 vs 1.6, respectively; HR = 0.73, 95% CI = 0.64 to 0.82; P < .001). For PC mortality, no statistically significant difference was observed between the SA and CA (HR = 0.85, 95% CI = 0.69 to 1.04) (with intention-to-screen analysis). To avoid one PC death, we needed to invite 1199 men to screening and to detect 25 PCs. We observed no difference in all-cause mortality between trial arms.
Conclusions
At 12 years, a relatively conservative screening protocol produced a small, non-statistically significant PC-specific mortality reduction in the Finnish trial, at the cost of moderate overdiagnosis.