BACKGROUND The aim of this study was to quantify the impact of organised mammography screening on breast cancer mortality across European regions. Therefore, a systematic review was performed including different types of studies from all European regions and stringently used clearly defined quality appraisal to summarise the best evidence. METHODS Six databases were searched including Embase, Medline and Web of Science from inception to March 2018. To identify all eligible studies which assessed the effect of organised screening on breast cancer mortality, two reviewers independently applied predefined inclusion and exclusion criteria. Original studies in English with a minimum follow-up of five years that were randomised controlled trials (RCTs) or observational studies were included. The Cochrane risk of bias instrument and the Newcastle-Ottawa Scale were used to assess the risk of bias. RESULTS Of the 5015 references initially retrieved, 60 were included in the final analysis. Those comprised 36 cohort studies, 17 case-control studies and 7 RCTs. None were from Eastern Europe. The quality of the included studies varied: Nineteen of these studies were of very good or good quality. Of those, the reduction in breast cancer mortality in attenders versus non-attenders ranged between 33% and 43% (Northern Europe), 43%-45% (Southern Europe) and 12%-58% (Western Europe). The estimates ranged between 4% and 31% in invited versus non-invited. CONCLUSION This systematic review provides evidence that organised screening reduces breast cancer mortality in all European regions where screening was implemented and monitored, while quantification is still lacking for Eastern Europe. The wide range of estimates indicates large differences in the evaluation designs between studies, rather than in the effectiveness of screening.

中文翻译：

---

在欧洲因筛查乳腺癌而降低特定于癌症的死亡率的证据：系统评价。

背景技术这项研究的目的是量化有组织的乳腺X线摄影筛查对整个欧洲地区乳腺癌死亡率的影响。因此，进行了系统评价，包括来自所有欧洲地区的不同类型的研究，并严格使用明确定义的质量评估来总结最佳证据。方法自成立至2018年3月，共检索了六个数据库，包括Embase，Medline和Web of Science。为鉴定所有评估有组织筛查对乳腺癌死亡率的影响的合格研究，两名评价者独立应用了预定的纳入和排除标准。包括至少5年随访的英语原始研究，随机对照试验（RCT）或观察性研究。使用Cochrane偏倚风险工具和纽卡斯尔-渥太华量表对偏倚风险进行评估。结果在最初检索的5015篇参考文献中，有60篇被纳入最终分析。这些包括36项队列研究，17项病例对照研究和7项RCT。没有一个来自东欧。纳入研究的质量各不相同：其中有19项研究的质量非常好。其中，服务员与非服务员的乳腺癌死亡率降低幅度在33％至43％（北欧），43％-45％（南欧）和12％-58％（西欧）之间。受邀者与未受邀者的估计值之间在4％到31％之间。结论本系统评价提供了证据，表明在所有实施和监控筛查的欧洲地区，有组织的筛查可降低乳腺癌的死亡率，而东欧仍然缺乏量化方法。估计范围广泛，表明研究之间的评估设计有很大差异，而不是筛选的有效性。