Flow cytometric DNA analysis of human solid tumors: a review of the interpretation of DNA histograms.

A survey of over 225 recent studies examining the relationship between the flow cytometric DNA analysis of solid tumors and clinical prognosis indicates that criteria used to classify DNA histograms are variable and often inconsistent with the recommendations proposed by the Convention on Nomenclature for DNA Cytometry. Numerous reports not only lack unambiguous descriptions of the histogram features used to differentiate diploid from aneuploid DNA distributions, but also inadequately describe the technical aspects of data acquisition, standardization, and inclusion or exclusion of subpopulations by gating. In many cases, the coefficient of variation of the diploid and aneuploid G0/1 peaks, which would allow an assessment of histogram quality, is not reported. Because of the differences in DNA histogram interpretation, extrapolation of the results among laboratories may be difficult and is probably not reliable. This review summarizes the criteria that have been used to classify the DNA histograms and illustrates the effects of these different classifiers on DNA ploidy analysis and clinical conclusions.