An overview of multi-variate analyses of prognostic variables with special reference to the role of cytoreductive surgery

Abstract
Background Cytoreductive surgery is still widely believed to be a cornerstone in the management of advanced ovarian cancer. In the absence of data from prospective randomized trials, multi-variate analysis can assist in evaluating the role of optimal surgical cytoreduction relative to other possible prognostic variables. Materials and methods Published analyses of prognostic variables have been reviewed and the consistency and repro-ducibility of variables have been considered. Results When reviewing the most recent literature it is obvious that there is a need to develop a consensus as to the most important patient characteristics which should be reported. Furthermore, these characteristics need to be standardized as do definitions such as toxicity, grading, and response criteria and duration. Subjective variables such as performance status, histological grading and typing, present a special problem as these lack reproducibility. The overview of multi-variate analyses for prognostic variables such as residual tumour size, tumour size prior to cytoreductive surgery, cisplatin therapy, grade, stage, histology, and performance status demonstrates that the impact of individual prognosticators depends on the indicators included in the analysis and that the importance of these variables could change as new technologies and treatments are introduced. Conclusions The collection of a single data base including all known variables reported for each patient with appropriate attention to the careful evaluation of subjective indicators should be undertaken, with a view to establishing a prognostic index. This would allow the relative risk for individual patients to be assessed.