Division of Gynecologic Oncology, National Hospital Organization, Hokkaido Cancer Center, 4-2 Kikusui, Shiroishi-ku, Sapporo, 003-0804, Japan.
Int J Clin Oncol. 2013 Apr;18(2):200-6. doi: 10.1007/s10147-012-0499-0. Epub 2012 Dec 1.
A consensus regarding the therapeutic role of lymphadenectomy in endometrial cancer has not been reached because of conflicting negative results of randomized controlled trials and positive results of a cohort study. Since the effects of new treatments tend to be overestimated in observational studies, positive results of an observational study should be validated by a future trial. However, special difficulties are presented in randomized controlled trials in surgery. External validity is important for guaranteeing the reliability of a result of the trial. Physicians' recruitment of eligible patients into a trial depends on the confidence of those physicians for a surgical procedure, workplace environment and feelings of personal responsibility relevant to patients' risk of recurrence. When two surgical procedures are compared in a randomized controlled trial, technical quality control may be reduced in the complicated surgery group due to experienced surgeons' non-participation. It is highly possible that the recruitment issue is a threat to external validity. Therefore, a randomized controlled trial may not be the best format for demonstrating the full benefits of complicated surgery. Multiple studies have demonstrated that the results of well-designed observational studies can be reliable and are comparable with those of randomized controlled trials. Journal editors and funding sources are requested to become more generous with observational studies, especially prospective cohort studies.
由于随机对照试验的结果相互矛盾，且队列研究的结果为阳性，因此对于淋巴结切除术在子宫内膜癌中的治疗作用尚未达成共识。由于新疗法的疗效在观察性研究中往往被高估，因此需要通过未来的试验来验证观察性研究的阳性结果。然而，手术中的随机对照试验存在特殊的困难。外部有效性对于保证试验结果的可靠性很重要。医生是否将符合条件的患者招募到试验中取决于他们对手术程序的信心、工作场所环境以及与患者复发风险相关的个人责任感。当在随机对照试验中比较两种手术方法时，由于经验丰富的外科医生不参与，复杂手术组的技术质量控制可能会降低。招募问题很可能对外部有效性构成威胁。因此，随机对照试验可能不是展示复杂手术全部益处的最佳形式。多项研究表明，精心设计的观察性研究的结果是可靠的，并且可以与随机对照试验的结果相媲美。期刊编辑和资金来源应更加支持观察性研究，特别是前瞻性队列研究。
