The methodology for conducting cancer clinical trials has undergone enormous changes over the past 25-30 years since the EORTC Data Center was created. The purpose of this paper is to highlight and to provide a historical perspective for the main methodological concepts, both practical and theoretical, which form the basis for the design and analysis of phase III cancer clinical trials within the EORTC Data Center. Some statistical aspects of other associated topics such as quality of life, health economics, meta-analysis and treatment outcome will also be briefly discussed. Finally, some future perspectives and topics for further statistical methodological research will be presented in order to spur statisticians to meet the challenge of efficiently designing and analysing the clinical trials of tomorrow.