BACKGROUND Despite enthusiasm for cancer screening, systematic reviews consistently fail to show that screening reduces all-cause mortality. This narrative review explores conceptual issues, and inconsistencies between evidence and opinion about screening. REVIEW We examined the interpretation of screening studies in relation to three intellectual traditions: (1) The relationship between prevention and cure; (2) Confirmation bias and the challenge of incorporating new data: less care may produce better outcomes than more care; (3) The answers to three structured questions about efficacy, effectiveness, and value of treatments proposed by Sir Archie Cochrane and Sir Austin Bradford Hill. SYNTHESIS When considering extensions of life expectancy or all-cause mortality, systematic reviews typically show cancer screening to have only small effects and often non-significant effects on all-cause mortality. Early diagnosis does not assure application of an intervention that alters the pathway toward demise. The interpretation of screening results is also affected by several known biases. Investigators and advocates are encumbered by an over focus on studies designed to determine if a treatment can work under ideal circumstances. To advance the field, we need a greater emphasis on evaluations that ask 'Does the treatment work under real-world conditions?', and 'Is the treatment worth it?' in terms of outcomes that are meaningful to patients.

中文翻译：

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如果我们测量对患者有效，可靠，特异且重要的终点，则对癌症筛查的建议将有所不同。

背景技术尽管热衷于癌症筛查，但系统评价始终未能表明筛查降低了全因死亡率。这篇叙述性评论探讨了概念性问题，以及关于筛查的证据和观点之间的矛盾。综述我们研究了与三种智力传统有关的筛查研究的解释：（1）预防和治愈之间的关系；（2）确认偏差和合并新数据的挑战：少护理可能比多护理产生更好的结果；（3）由A​​rchie Cochrane爵士和Austin Bradford Hill爵士提出的有关功效，功效和治疗价值的三个结构性问题的答案。综合考虑延长预期寿命或全因死亡率时，系统评价通常显示，癌症筛查对全因死亡率仅具有很小的影响，并且通常没有显着影响。早期诊断不能确保应用改变死亡途径的干预措施。筛选结果的解释也受到几种已知偏见的影响。研究人员和倡导者对设计用来确定某种治疗方法在理想情况下是否可以有效进行的研究过于关注。为了推动该领域的发展，我们需要更加重视以下评估：“在现实条件下治疗是否有效？”以及“治疗值得吗？” 就对患者有意义的结果而言。筛选结果的解释也受到几种已知偏见的影响。研究人员和倡导者对设计用来确定某种治疗方法在理想情况下是否可以有效进行的研究过于关注。为了推动这一领域的发展，我们需要更加重视以下评估：“在现实条件下治疗是否有效？”和“治疗值得吗？” 就对患者有意义的结果而言。筛选结果的解释也受到几种已知偏见的影响。研究人员和倡导者对设计用来确定某种治疗方法在理想情况下是否可以有效进行的研究过于关注。为了推动该领域的发展，我们需要更加重视以下评估：“在现实条件下治疗是否有效？”以及“治疗值得吗？” 就对患者有意义的结果而言。