Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, INF 581, 69120 Heidelberg, Germany German Cancer Consortium, Heidelberg, Germany
Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, INF 581, 69120 Heidelberg, Germany Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany.
BMJ. 2014 Apr 9;348:g2467. doi: 10.1136/bmj.g2467.
To review, summarise, and compare the evidence for effectiveness of screening sigmoidoscopy and screening colonoscopy in the prevention of colorectal cancer occurrence and deaths.
Systematic review and meta-analysis of randomised controlled trials and observational studies.
PubMed, Embase, and Web of Science. Two investigators independently extracted characteristics and results of identified studies and performed standardised quality ratings.
Randomised controlled trials and observational studies in English on the impact of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality in the general population at average risk.
For screening sigmoidoscopy, four randomised controlled trials and 10 observational studies were identified that consistently found a major reduction in distal but not proximal colorectal cancer incidence and mortality. Summary estimates of reduction in distal colorectal cancer incidence and mortality were 31% (95% confidence intervals 26% to 37%) and 46% (33% to 57%) in intention to screen analysis, 42% (29% to 53%) and 61% (27% to 79%) in per protocol analysis of randomised controlled trials, and 64% (50% to 74%) and 66% (38% to 81%) in observational studies. For screening colonoscopy, evidence was restricted to six observational studies, the results of which suggest tentatively an even stronger reduction in distal colorectal cancer incidence and mortality, along with a significant reduction in mortality from cancer of the proximal colon. Indirect comparisons of results of observational studies on screening sigmoidoscopy and colonoscopy suggest a 40% to 60% lower risk of incident colorectal cancer and death from colorectal cancer after screening colonoscopy even though this incremental risk reduction was statistically significant for deaths from cancer of the proximal colon only.
Compelling and consistent evidence from randomised controlled trials and observational studies suggests that screening sigmoidoscopy and screening colonoscopy prevent most deaths from distal colorectal cancer. Observational studies suggest that colonoscopy compared with flexible sigmoidoscopy decreases mortality from cancer of the proximal colon. This added value should be examined in further research and weighed against the higher costs, discomfort, complication rates, capacities needed, and possible differences in compliance.
综述、总结和比较乙状结肠镜筛查和结肠镜筛查在预防结直肠癌发生和死亡方面的有效性证据。
随机对照试验和观察性研究的系统评价和荟萃分析。
PubMed、Embase 和 Web of Science。两名调查员独立提取并比较了所确定研究的特征和结果，并进行了标准化质量评价。
以英文发表的关于乙状结肠镜筛查和结肠镜筛查对一般人群平均风险结直肠癌发病率和死亡率影响的随机对照试验和观察性研究。
对于乙状结肠镜筛查，共确定了 4 项随机对照试验和 10 项观察性研究，这些研究均一致发现远端结直肠癌发病率和死亡率显著降低，但近端结直肠癌发病率和死亡率无显著降低。意向性筛查分析中，远端结直肠癌发病率和死亡率的综合估计值分别为 31%（95%置信区间 26%至 37%）和 46%（33%至 57%），随机对照试验的方案分析中分别为 42%（29%至 53%）和 61%（27%至 79%），观察性研究中分别为 64%（50%至 74%）和 66%（38%至 81%）。对于结肠镜筛查，证据仅限于 6 项观察性研究，这些研究结果初步表明，远端结直肠癌发病率和死亡率降低更为显著，同时近端结肠癌的死亡率也显著降低。对乙状结肠镜筛查和结肠镜筛查观察性研究结果的间接比较表明，即使近端结肠癌的死亡风险降低仅具有统计学意义，但结肠镜筛查后结直肠癌和结直肠癌死亡的风险仍降低 40%至 60%。
来自随机对照试验和观察性研究的令人信服且一致的证据表明，乙状结肠镜筛查和结肠镜筛查可预防大多数远端结直肠癌死亡。观察性研究表明，与乙状结肠镜筛查相比，结肠镜筛查可降低近端结肠癌的死亡率。在进一步的研究中，应该对这种附加价值进行检查，并权衡其较高的成本、不适、并发症发生率、所需能力以及可能存在的依从性差异。
