DNA flow cytometric measurements in breast cancer: a review of the instrumentation principles and clinical significance.

Breast cancer treatment remains a controversial and challenging issue. Treatment of this disease is often guided by the clinical stage and type of tumor present, as well as information provided by a variety of prognostic indicators which can be employed. DNA analysis by flow cytometry is a relatively new technique that is emerging as a powerful tool to predict the biologic behavior of breast tumors. A majority of studies have demonstrated that the S-phase fraction measured by DNA flow cytometric is an independent predictor of patient outcome. There is less conclusive information regarding the association of DNA ploidy with the clinical behavior of breast malignancies, although, tumor grading often closely parallels this DNA parameter. New flow cytometry methodology involves multiparameter analysis that allows a simultaneous examination of DNA ploidy and cell cycle analysis with surface or internal molecules. This newer approach permits a precise delineation of DNA characteristics in distinct cell populations within a tumor and will likely enhance the utility of this procedure in determining the biologic behavior of the breast tumor.