Department of Public Health & Epidemiology, School of Medicine, University of Birmingham, Edgbaston, United Kingdom.
Cancer Lett. 2008 Apr 8;262(1):48-53. doi: 10.1016/j.canlet.2007.11.032. Epub 2008 Jan 2.
A number of authors have found that there exists a positive relationship between progression-free survival and overall survival in clinical trials of cancer treatments for particular types of metastatic cancer. However, such an outcome is consistent with an increase in progression-free survival generally leading to an increase, a decrease or no change in survival following disease progression (post-progression survival) and which of these theories is valid has yet to be thoroughly investigated.
To test theories of this nature in relation to the use of chemotherapy in treating four different types of metastatic cancer by performing a systematic search of published clinical trials. The four types of metastatic cancer are metastatic breast cancer, colorectal cancer, hormone-refractory prostate cancer and non-small-cell lung cancer.
The data sources were systematic reviews of randomized controlled trials (RCTs) published between January 1990 and June 2007 that appear in Medline or the Cochrane Database of Systematic Reviews and the abstracts of articles referenced in such reviews. For an RCT to be included in the study, chemotherapy had to be administered to both the treatment and control groups and the chemical composition of the chemotherapy had to be different between the two groups. The median time to disease progression and the median overall survival time had to be reported in the data sources.
The trial data found through the systematic search shows much greater support for the theory that, for all four types of metastatic cancer being considered, changes in post-progression survival are uncorrelated with changes in time to disease progression than for the theory that gains in post-progression survival are proportional to gains in time to progression.
The theories about the relationship between progression-free and post-progression survival in cancer treatment that have been examined in this study are worthy of further investigation.
许多作者发现，在针对特定类型转移性癌症的癌症治疗临床试验中，无进展生存期与总生存期之间存在正相关关系。然而，这种结果与无进展生存期的增加通常会导致疾病进展后（进展后生存）的生存增加、减少或无变化的理论一致，而哪种理论是有效的，尚未得到彻底研究。
通过对已发表的临床试验进行系统检索，测试与使用化疗治疗四种不同类型转移性癌症相关的这种性质的理论。这四种类型的转移性癌症是转移性乳腺癌、结直肠癌、激素难治性前列腺癌和非小细胞肺癌。
数据来源是 1990 年 1 月至 2007 年 6 月期间发表的系统评价的 Medline 或 Cochrane 系统评价数据库以及这些综述中引用的文章摘要。为了使 RCT 纳入研究，治疗组和对照组都必须接受化疗，并且两组之间的化疗化学成分必须不同。数据来源中必须报告疾病进展的中位时间和总生存期的中位时间。
通过系统搜索发现的试验数据为以下理论提供了更多支持，即对于正在考虑的所有四种类型的转移性癌症，进展后生存的变化与疾病进展时间的变化无关，而不是进展后生存的增加与进展时间的增加成正比的理论。
本研究中检查的关于癌症治疗中无进展生存期和进展后生存期之间关系的理论值得进一步研究。
