1月6日，《国立癌症研究所杂志》在线发表的有关前列腺、肺、结直肠和卵巢(PLCO)筛查试验的13年随访结果"Prostate Cancer Screening in the Randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial: Mortality Results after 13 Years of Follow-up"表明，每年接受前列腺癌筛查者死于前列腺癌的几率并不低于接受常规随访和随机筛查的男性。
这项研究由华盛顿大学圣路易斯分校的Gerald L. Andriole博士及其同事进行，共纳入76,693名55~74岁的男性，旨在评价在既有随机筛查基础上增加每年1次筛查的效果并比较两者的预后。这些男性被随机分成2组，干预组(n=38,343)接受为期6年的每年1次前列腺特异性抗原(PSA)筛查和为期4年的每年1次直肠指检，对照组(n=38,350)接受常规随访(包括医生建议的筛查)。在研究开始前，44%的受试者曾接受PSA筛查。研究期间，对照组与干预组接受PSA检查的受试者比例分别为52%和100%。
研究者此前曾报道了随访7年和10年的结果。随访7年的结果显示，与常规处理相比，每年1次筛查与前列腺癌诊断率增加有关，但2组的前列腺癌死亡率和全因死亡率相同。同样，随访10年的结果显示，干预组死亡率与对照组无明显差异(N. Engl. J. Med. 2009;360:1320-1328)。
截至2009年12月31日的13年随访结果显示，干预组38,340名受试者中的4,250名和对照组38,345名受试者中的3,815名被诊断为前列腺癌。干预组和对照组的前列腺癌累计发生率分别为108.4/10,000(人·年) 和97.1/10,000(人·年)，干预组的发生率相对明显增加12%。在前列腺癌诊断方面，干预组401例受试者和对照组454例受试者被诊断为高级别前列腺癌，Gleason评分为8~10分。随访13年时，干预组和对照组的死亡例数分别为158例和145例，前列腺癌累计死亡率分别为3.7/ 10,000(人·年)和3.4/ 10,000(人·年)，组间差异不显著。研究者采用泊松回归模型分析各组前列腺癌死亡率和相对死亡风险与年龄、合并症和试验前PSA检查之间的交互作用，但未发现显著交互作用。2组的全因死亡(除了前列腺癌、肺癌和结直肠癌所致死亡之外)率存在临界统计学差异，干预组和对照组的死亡例数分别为5,783例和5,982例。干预组和对照组的非PLCO癌症死亡率分别为23%和22%，缺血性心脏病死亡率分别为21%和19%。
该研究的局限性在于混杂的诊断效应可能掩盖了前列腺癌死亡率的降低。换言之，干预组有较多死亡归因于前列腺癌。支持这种可能性的依据在于干预组的全因死亡率显著低于对照组。干预组其他原因所致的死亡率较高，因此死亡归因方面的错误或许不是干预组前列腺癌死亡率高的原因。
研究者计划将随访时间延长至15年，以进一步观察死亡率。（生物谷Bioon.com）
doi:10.1093/jnci/djr500
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Prostate Cancer Screening in the Randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial: Mortality Results after 13 Years of Follow-up
Gerald L. Andriole, E. David Crawford, Robert L. Grubb III, Saundra S. Buys, David Chia, Timothy R. Church, Mona N. Fouad, Claudine Isaacs,et al.
Background The prostate component of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial was undertaken to determine whether there is a reduction in prostate cancer mortality from screening using serum prostate-specific antigen (PSA) testing and digital rectal examination (DRE). Mortality after 7–10 years of follow-up has been reported previously. We report extended follow-up to 13 years after the trial.
Methods A total of 76 685 men, aged 55–74 years, were enrolled at 10 screening centers between November 1993 and July 2001 and randomly assigned to the intervention (organized screening of annual PSA testing for 6 years and annual DRE for 4 years; 38 340 men) and control (usual care, which sometimes included opportunistic screening; 38 345 men) arms. Screening was completed in October 2006. All incident prostate cancers and deaths from prostate cancer through 13 years of follow-up or through December 31, 2009, were ascertained. Relative risks (RRs) were estimated as the ratio of observed rates in the intervention and control arms, and 95% confidence intervals (CIs) were calculated assuming a Poisson distribution for the number of events. Poisson regression modeling was used to examine the interactions with respect to prostate cancer mortality between trial arm and age, comorbidity status, and pretrial PSA testing. All statistical tests were two-sided.
Results Approximately 92% of the study participants were followed to 10 years and 57% to 13 years. At 13 years, 4250 participants had been diagnosed with prostate cancer in the intervention arm compared with 3815 in the control arm. Cumulative incidence rates for prostate cancer in the intervention and control arms were 108.4 and 97.1 per 10 000 person-years, respectively, resulting in a relative increase of 12% in the intervention arm (RR = 1.12, 95% CI = 1.07 to 1.17). After 13 years of follow-up, the cumulative mortality rates from prostate cancer in the intervention and control arms were 3.7 and 3.4 deaths per 10 000 person-years, respectively, resulting in a non-statistically significant difference between the two arms (RR = 1.09, 95% CI = 0.87 to 1.36). No statistically significant interactions with respect to prostate cancer mortality were observed between trial arm and age (Pinteraction = .81), pretrial PSA testing (Pinteraction = .52), and comorbidity (Pinteraction = .68).
Conclusions After 13 years of follow-up, there was no evidence of a mortality benefit for organized annual screening in the PLCO trial compared with opportunistic screening, which forms part of usual care, and there was no apparent interaction with age, baseline comorbidity, or pretrial PSA testing.
