IMPROVED METHODOLOGY FOR ANALYZING LOCAL AND DISTANT RECURRENCE
IMPROVED METHODOLOGY FOR ANALYZING LOCAL AND DISTANT RECURRENCE
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DOI：
10.1200/jco.1990.8.3.548
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发表时间：
1990-03-01
影响因子：
45.3
通讯作者：
HARRIS, JR
中科院分区：
文献类型：
--
作者：
GELMAN, R;GELBER, R;HARRIS, JR
放射治疗和/或手术治疗癌症的研究经常使用精算方法来估计局部失败的时间曲线，并将这两条曲线与最初为生存数据开发的统计方法进行比较。在这样的分析中，先在远处失败或在局部失败之前死亡的患者被认为是对局部失败时间的审查。虽然这些计算的算术通常是正确的，但对结果的解释几乎普遍是错误的。例如，保乳治疗后乳房复发时间的精算Kaplan-Meier曲线始终高估了从随后的乳房切除术中受益的患者的百分比。精算方法要求假设到局部故障的时间和到远处故障的时间在统计上是独立的。对于大多数人类恶性肿瘤来说，这不是一个合理的假设，因为总是有一些患者亚组具有高风险的局部和远程失败风险，而一些患者亚组存在任何一种类型失败的低风险。在没有独立假设的情况下，到达局部失效的时间分布不能很好地定义。基本的问题是，估计局部失败的时间属于分析“竞争风险”的范畴，因为导致失败的各种原因都在争夺同一个患者。因此，不能将特定治疗方法对局部衰竭的影响与其对远处衰竭的影响分开来评估。这份报告解释了统计独立性、不可识别性和竞争风险的概念，并说明了使用精算方法评估局部肿瘤控制的陷阱。针对局部故障分析问题，我们提出了一种分两步进行的解决方案：首先分析(任意站点)首次故障发生的时间，然后分析首次故障站点的分布。
Studies of radiation therapy and/or surgery in the treatment of cancer frequently use actuarial methods to estimate curves of time to local failure and compare two such curves with statistical methods originally developed for survival data. In such analyses, patients who fail first in distant sites or die before local failure are considered censored for time to local failure. While the arithmetic of these calculations is usually correct, the interpretation of the results is almost universally incorrect. For example, an actuarial Kaplan-Meier curve of time to breast recurrence after breast conserving treatment consistently overestimates the percentage of patients who would benefit from a subsequent mastectomy. Actuarial methods require the assumption that time to local failure and time to distant failure are statistically independent. For most human malignancies this is not a reasonable assumption, since there are always some patient subgroups at high risk of both local and distant failure and some patient subgroups at low risk for either type of failure. Without the assumption of independence, the time to local failure distribution is not well defined. The basic problem is that estimating time to local failure falls into the category of analyzing "competing risks," since the various causes of failure are competing for the same patient. For this reason, the effects of a particular treatment on local failure cannot be assessed separately from its effects on distant failure. This report explains the concepts of statistical independence, nonidentifiability, and competing risks and illustrates the pitfalls of using actuarial methods to assess local tumour control. We propose a solution to the problem of analyzing local failure, which uses a two-step procedure: first analyzing time to first failure (in any site) and then analyzing the distribution of sites of first failure.