Meta-analyses of randomised clinical trials in oncology

Lancet Oncol. 2001 Aug;2(8):475-82. doi: 10.1016/S1470-2045(01)00453-3.


A meta-analysis is a quantitative synthesis of randomised clinical trials, used to evaluate moderate treatment effects in oncology. It is complementary to large-scale trials. We describes the principles, methods, and limits of meta-analyses. The gold standard for a meta-analysis is to obtain individual patient data directly from each principal investigator, but this is time-consuming and costly. The main steps of a meta-analysis using individual patient data are described. Multidisciplinary collaboration is needed for clinical insight and critical review of the data and results. Meta-analysis should include an evaluation of the trial quality, a quantification of the overall treatment effect, a study of the variations seen in this effect between trials, and pre-planned exploratory analyses to identify groups of patients who may benefit more from the treatment. Statistical methods are explained using real working examples. Since literature-based meta-analysis can lead to seriously biased assessments, meta-analyses of individual patient data should be undertaken systematically when long-term follow-up is needed, when a detailed analysis is important, or when the literature-based meta-analyses are not in agreement. The main factors which influence the quality of a meta-analysis are discussed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Data Interpretation, Statistical
  • Forecasting
  • Humans
  • Meta-Analysis as Topic*
  • Neoplasms / therapy*
  • Randomized Controlled Trials as Topic* / standards