Review of factors influencing the response of experimental brain tumors to therapy.

This review summarizes the problems and pitfalls encountered when increased life span studies are performed with brain tumor model systems. The biological factors reviewed include tumor size and growth rate, the immune response, cell kinetics, and cell recovery processes. The analytical factors reviewed include data collection, data presentation, covariate analysis, and statistical analysis. Examples of how these factors can influence the ultimate interpretation of results from brain tumor therapy trials are presented.