Critical appraisal of in situ cell kinetic measurements as response predictors in human tumors

Abstract

The purpose of this article is to review the potential advantages of measuring cell kinetic parameters, to indicate in which settings they are likely to be most useful and to point out some deficiencies in present methodologies. This will be done by attempting to answer a series of fundamental questions. Cell kinetics crucially affect many factors related to the timing of response after therapy. These include the time and rate of cell death, the rate of regression, the rate of reoxygenation, and the time to recurrence. Proliferation of surviving cells can also occur during gaps in treatment, whether the treatment be radiotherapy or chemotherapy, and whether the gaps are short (eg, between daily treatments) or longer (eg, a weekend; weeks between treatment courses; weeks between surgery and adjuvant radiotherapy or chemotherapy), l The end result of such proliferation is the partial repopulation of a tumor before treatment is ended. In other words, repopulation can compete with treatment-induced cell killing, reducing the effectiveness of the treatment. There