Abstract
Clinically, cytometric DNA (ploidy and proliferative fraction) analysis is primarily used in the determination of tumor prognosis. This determination has a clinical impact primarily in low stage tumors where therapeutic options are available, rather than in higher stage tumors that will be treated the same independent of their ploidy or proliferative fraction. In general, the best available data indicate that for most tumors aneuploidy is an indicator of more aggressiveness. Ploidy analysis is independent of other prognostic indicators in many tumors and is the most significant prognostic indicator in some. More recent data suggest that proliferative fraction, the percentage of tumor cells in the S-phase of the cell cycle, may be as important an indicator of tumor prognosis as simple presence of aneuploidy. However, the poor interlaboratory reproducibility of S-phase measurements as currently performed limits the general applicability of this measurement in the management of patients.